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1.	Carlsson, F, et al. (author) Protein-polyelectrolyte cluster formation and redissolution: A Monte Carlo study 2003 In: Journal of The American Ceramic Society. - : American Chemical Society (ACS). - 0002-7820 .- 1551-2916. ; 125:10, s. 3140-9 Journal article (peer-reviewed)abstract Aqueous solutions of proteins and oppositely charged polyelectrolytes were studied at different polyelectrolyte chain length, ionic strength, and protein-protein interaction potential as a function of the polyelectrolyte concentration. One of the protein models used represented lysozyme in aqueous environment. The model systems were solved by Monte Carlo simulations, and their properties were analyzed in terms of radial distribution functions, structure factors, and cluster composition probabilities. In the system with the strongest electrostatic protein-polyelectrolyte interaction the largest clusters were formed near or at equivalent amount of net protein charge and polyelectrolyte charge, whereas in excess of polyelectrolyte a redissolution appeared. Shorter polyelectrolyte chains and increased ionic strength lead to weaker cluster formation. An inclusion of nonelectrostatic protein-protein attraction promoted the protein-polyelectrolyte cluster formation.
2.	Halthur, Tobias, et al. (author) Stability of Polypeptide Multilayers As Studied by in Situ Ellipsometry : Effects of Drying and Post-Buildup Changes in Temperature and pH 2004 In: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 126, s. 17009-17015 Journal article (peer-reviewed)abstract Polyelectrolyte multilayers (PEM) of poly(L-glutamic acid) (PGA) and poly(L-lysine) (PLL) with an initial layer of polyethyleneimine (PEI) were built on silica and titanium surfaces using the layer-by-layer (LbL) technique. The stability of the film during drying/rewetting, temperature cycles, and pH shifts was studied in situ by means of ellipsometry. The film thickness was found to decrease significantly (approximately 70%) upon drying, but the original film thickness was regained upon rewetting, and the buildup could be continued. The thickness in the dry state was found to be extremely sensitive to ambient humidity, needing several hours to equilibrate. Changes in temperature and pH were also found to influence the multilayer thickness, leading to swelling and deswelling of as much as 8% and 10-20% respectively. The film does not necessarily regain its original thickness as the pH is shifted back, but instead shows clear signs of hysteresis.
3.	Tyrode, Eric, et al. (author) Adsorption of CTAB on hydrophilic silica studied by linear and nonlinear optical spectroscopy 2008 In: Journal of The American Ceramic Society. - : American Chemical Society. - 0002-7820 .- 1551-2916 .- 0002-7863 .- 1520-5126. ; 130:51, s. 17434–17445- Journal article (peer-reviewed)abstract Vibrational sum-frequency spectroscopy (SFS) and total internal reflection Raman scattering (TIR Raman) have been used to study the adsorption of hexadecyltrimethylammonium bromide (CTAB) to hydrophilic silica. These two complementary techniques permit the determination of the adsorbed amount with a sensitivity of 1% of the maximum surface coverage, changes in the average tilt of the adsorbed molecules, the presence of asymmetric aggregates in the adsorbed film, and the structure and orientation of the water molecules in the interfacial region. The TIR Raman spectra show a monotonic increase with CTAB concentration with no measurable changes in the relative intensities of the different polarization combinations probed, implying that no significant changes occur in the conformational order of the hydrocarbon chain. In the sum-frequency (SF) spectra, no detectable peaks from the surfactant headgroup and hydrophobic chain were observed at any surface coverage. Major changes are observed in the water bands of the SF spectra, as the originally negatively charged silica surface becomes positively charged with an increase in the adsorbed amount, inducing a change in the polar orientation of the water molecules near the surface. The detection limits for hydrocarbons chains in the SF spectra were estimated by comparison with the SF spectrum of a disordered octadecyltrichlorosilane monolayer. The simulations demonstrate that the asymmetry in the adsorbed CTAB layer at any concentration is less than 5% of a monolayer. The results obtained pose severe constraints on the possible structural models, in particular at concentrations below the critical micellar concentration where information is scarce. The formation of hemimicelles, monolayers and other asymmetric aggregates is ruled out, with centrosymmetric aggregates forming from early on in the adsorption process.
4.	Tyrode, Eric, et al. (author) Hydration State of Non-ionic Surfactant Monolayers at the Liquid/Vapor Interface : Structure Determination by Vibrational Sum Frequency Spectroscopy 2005 In: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 127, s. 16848-16859 Journal article (peer-reviewed)abstract The OH stretching region of water molecules in the vicinity of nonionic surfactant monolayers has been investigated using vibrational sum frequency spectroscopy (VSFS) under the polarization combinations ssp, ppp, and sps. The surface sensitivity of the VSFS technique has allowed targeting the few water molecules present at the surface with a net orientation and, in particular, the hydration shell around alcohol, sugar, and poly(ethylene oxide) headgroups. Dramatic differences in the hydration shell of the uncharged headgroups were observed, both in comparison to each another and in comparison to the pure water surface. The water molecules around the rigid glucoside and maltoside sugar rings were found to form strong hydrogen bonds, similar to those observed in tetrahedrally coordinated water in ice. In the case of the poly(ethylene oxide) surfactant monolayer a significant ordering of both strongly and weakly hydrogen bonded water was observed. Moreover, a band common to all the surfactants studied, clearly detected at relatively high frequencies in the polarization combinations ppp and sps, was assigned to water species located in proximity to the surfactant hydrocarbon tail phase, with both hydrogen atoms free from hydrogen bonds. An orientational analysis provided additional information on the water species responsible for this band.
5.	Ikoma, T., et al. (author) Protein adsorption on hydroxyapatite nanosensors with different crystal sizes studied in situ by a quartz crystal microbalance with the dissipation method 2009 In: Journal of the American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 92:5, s. 1125-1128 Journal article (peer-reviewed)abstract Hydroxyapatite (HAp) nanocrystals with different crystal sizes were deposited by the electrophoretic deposition method on the gold surface of a quartz crystal microbalance with a dissipation probe. The nanosensors formed this way were used to elucidate the adsorption mechanism of proteins with a similar pI value. The crystal sizes and the area of the a-plane affected only the adsorption amount of human serum albumin, but not that of bovine plasma fibrinogen. The viscoelastic property, Delta D/Delta f, of each absorbed layer on the nanosensors was almost constant. The protein adsorption mechanism can be explained as follows: the dissociated carboxyl groups (negative charge) of albumin were interacted with calcium ions and the hydrated amine groups (positive charge) at the alpha C domain of fibrinogen were with phosphate ions on the HAp surface.
6.	Weidow, Jonathan, 1980, et al. (author) Transition Metal Solubilities in WC in Cemented Carbide Materials 2011 In: Journal of the American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 94:2, s. 605-610 Journal article (peer-reviewed)abstract Solubilities of different transition metals in WC in cemented carbides at around 1700 K were determined with atom probe tomography. Ta had the highest solubility, followed by Nb, Cr, and V, all with atom fractions in the 10−3 range. Ti and Mn showed lower, yet detectable, solubilities in the 10−6 or 10−5 range. Zr and Co solubilities were too low to be measured. The results were compared with the theoretically calculated solubilities using density functional theory. These calculations predicted that Ta, Nb, V, and Cr should have the highest solubility, all in the 10−4 or 10−3 range. Ti was predicted to have a lower solubility (10−5 range) and Co, Hf, and Zr even lower (10−8 or 10−7 range).
7.	Ahmed, Istaq, 1972, et al. (author) Crystal structure and proton conductivity of BaZr0.9Sc0 2008 In: Journal of the American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 91:9, s. 3039-3044 Journal article (peer-reviewed)abstract Solid-state sintering has been used to prepare the perovskite BaZr0.9Sc0.1O3-delta. Analysis of X-ray powder diffraction data shows that an increase of the unit cell parameter, a, was observed after deuteration. Rietveld analysis of room-temperature neutron powder diffraction data confirmed cubic symmetry (space group Pm-3m). Dynamic thermogravimetric analysis indicates that the hydration process occurs below 335 degrees C and approximately 58% of the theoretical number of protonic defects can be filled. The presence of protons/deutrons is seen from the strong O-H/O-D stretch band in the infrared spectrum of the hydrated/deuterated samples. The proton conductivity of a prehydrated sample was investigated under dry and wet Ar atmospheres
8.	Akhtar, Farid, et al. (author) Colloidal Processing and Thermal Treatment of Binderless Hierarchically Porous Zeolite 13X Monoliths for CO2 Capture 2011 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 94:1, s. 199-205 Journal article (peer-reviewed)abstract Adsorbents with high surface area are potential candidates forefficient postcombustion CO2 capture. Binderless zeolite 13Xmonoliths with a hierarchical porosity and high CO2 uptakehave been produced by slip casting followed by pressurelessthermal treatment. The zeolite powder displayed an isoelectricpoint at pH 4.7 and electrostatically stabilized suspensions couldbe prepared at alkaline pH. The volume fraction-dependentsteady shear viscosity could be fitted to a modified Krieger–Dougherty model with a maximum volume fraction of 0.66. Thenarrow temperature range where monoliths could be producedwithout significant loss of the microporous surface area wasidentified and related to the phase behavior of the 13X material.Slip casting of concentrated suspensions followed by thermaltreatment of the powder bodies at a temperature of 8001Cwithout holding time resulted into strong hierarchically porouszeolite 13X monolith that displayed a CO2 uptake larger than29 wt%.
9.	Akhtar, Farid, et al. (author) Hierarchically Porous Ceramics from Diatomite Powders by Pulsed Current Processing 2009 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 92:2, s. 338-343 Journal article (peer-reviewed)abstract Hierarchically porous ceramic monoliths have been fabricated by pulsed current processing (PCP) of diatomite powders. The partial sintering behavior of the porous diatomite powders during PCP or spark plasma sintering was evaluated at temperatures between 600 degrees and 850 degrees C. Scanning electron microscopy and mercury porosimetry measurements showed that the PCP method was able to bond the diatomite powder together into relatively strong monoliths without significantly destroying the internal pores of the diatomite powder at a temperature range of 700 degrees-750 degrees C. Little fusion at the particle contact points occurred at temperatures below 650 degrees C while the powder showed partial melting and collapse of both the interparticle pores and the internal structure at temperatures above 800 degrees C.
10.	Ali, Sharafat, 1976-, et al. (author) Glasses in the Ba–Si–O–N System 2011 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 94:9, s. 2912-2917 Journal article (peer-reviewed)abstract The preparation and properties of Ba–Si–O–N glasses arereported. These oxynitride glasses were prepared by meltingmixtures of BaH2, SiO2, and Si3N4 powders in a nitrogenatmosphere at 1550°–1700°C. The glasses were characterized by X-ray powder diffraction, differential thermal analysis, and scanning electron microscopy. Final glass compositions were calculated from analyses obtained by energy dispersive X-ray(EDX) spectroscopy and combustion analysis, for cation and anion compositions, respectively. The glasses were found to behomogenous, translucent gray to opaque black, and consists of N contents of up to 42 equiv% and Ba contents of up to 36 equiv%. Determined glass densities varied between 3.27 and 4.18 g/cm3, and calculated molar volumes varied between1 0.28 and 11.11 cm3/mol. Both density and molar volume increase with Ba content. Glass compactness (0.45–0.49), glasstransition temperature (786°–905°C), and microhardness (7.93–9.56 GPa) were found to increase linearly with N content. There fractive index increased from 1.66 to 1.91 and was found tobe strongly correlated with the amounts of Ba and N.
11.	Bartek, Alena, et al. (author) Yttrium α-Sialon Ceramics by Hot Isostatic Pressing and Post-Hot Isostatic Pressing 1992 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 75:2, s. 432-439 Journal article (peer-reviewed)abstract Dense α-sialon materials were produced by hot isostatic pressing (HIP) and post-hot isostatic pressing (post-HIP) using compositions with the formula Yx(Si12-4.5x, Al4.5x)-(O1.5x,N16-1.5x) with 0.1 ≤x ≤ 0.9 and with the same compositions with extra additions of yttria and aluminum nitride. X-ray diffraction analyses show how the phase content changes from large amounts of β-sialon (x = 0.1) to large amounts of α-sialon (x = 0.4) and increasing amounts of mellilite and sialon polytypoids (x = 0.8). Samples HIPed at 1600°C for 2 h contained unreacted α-silicon nitride, while those HIPed at 1750°C for 1 h did not. This could be due to the fact that the time is to short to achieve equilibrium or that the high pressure (200 MPa) prohibits α-sialon formation. Sintering at atmospheric pressure leads to open porosity for all compositions except those with excess yttria. Therefore, only samples with excess yttria were post-HIPed. Microstructrual analyses showed that the post-HIPed samples had the highest α-sialon content. A higher amount of α-sialon and subsequently a lower amount of intergranular phase were detected at x = 0.3 and x = 0.4 in the post-HIPed samples in comparison to the HIPed. The hardness (HV10) and fracture toughness (KIC) did not differ significantly between HIPed and post-HIPed materials but vary with different x values due to different phase contents. Measurements of cell parameters for all compositions show a continuous increase with increasing x value which is enhanced by high pressure at high x values.
12.	Bergström, L., et al. (author) Probing polymeric stabilization in nonaqueous media by direct measurements 2000 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 83:1, s. 217-219 Journal article (peer-reviewed)abstract The steric repulsion induced by adsorbed layers of the commercial dispersant Hypermer KD3 has been probed by direct measurements in decalin. The forces are long range (commencing at 30-40 nm) and repulsive, and the distance dependence can be modeled with a simple scaling theory expression valid for polymer brushes. We obtain layer thicknesses of similar to 9-15 nm for the compressed layers, depending on KD3 concentration, whereas the undisturbed layers have a thickness of similar to 23-24 nm, independent of polymer concentration. Comparison of the measured interaction lengths with previous layer thickness estimates based on rheological studies shows that the polymer layers are compressed in dense suspensions.
13.	Cai, Yanbing, et al. (author) Sialon Ceramics Prepared by Using CaH2 as a Sintering Additive 2008 In: Journal of the American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 91:9, s. 2997-3004 Journal article (peer-reviewed)abstract In developing elongated a-sialon grains, a nitrogen-rich liquidphase sintering method was introduced by using CaH2 as asintering aid, so as to vary the N/O ratio of the liquid phaseformed in the sintering process while keeping the Si/Al ratiosconstant. With increasing addition the phase contents changedfrom single b-sialon to dual b/a-sialons and to single Ca-a-sialon.At low N/O ratios the microstructures contained mainlyequiaxed b-sialon grains, and at high N/O ratios well facetedelongated Ca-a-sialon grains. The improved toughness(KIC57.8 MPa .m1/2) and hardness (HV10517.5 GPa) propertiescan be attributed to the formation of interlocked microstructures.High-temperature compressive deformation testsindicated that the deformation onset temperature is determinedmainly by the Si/Al and N/O ratios, whereas the deformationrate is affected by the microstructure, i.e., the morphology andamounts of elongated a-sialon grains and residual glass phase,especially for the sialons with low N/O ratios.
14.	Carlsson, Mats, et al. (author) Synthesis and characterisation of Ti0.33Ta0.33Nb0.33C and Ta0.33Ti0.33 Nb0.33CxN1-x whiskers 1999 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 82:8, s. 1969-1976 Journal article (peer-reviewed)
15.	Ekstrand, Åsa, et al. (author) Homogeneous WC–Co-Cemented Carbides from a Cobalt-Coated WC Powder Produced by a Novel Solution-Chemical Route 2007 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 90:11, s. 3449-3454 Journal article (peer-reviewed)abstract A solution chemical route to cobalt-coated WC-powder is described that allows for the preparation of WC–Co powders and compacts having a carbon content very close to the desired carbon content even under an inert atmosphere. The microstructural homogeneity in the sintered WC–Co composites when using the Co-coated grains was found to be superior as compared with conventionally mill-mixed powders, and the structural changes in the individual WC-grains were found to be much smaller, which is ascribed mainly to the fact that the coated grains do not require a grinding step leading to the formation of a tail of smaller WC grain sizes.
16.	Eriksson, Mirva, et al. (author) Ferroelectric Domain Structures and Electrical Properties of Fine-Grained Lead-Free Sodium Potassium Niobate Ceramics 2011 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 94:10, s. 3391-3396 Journal article (peer-reviewed)abstract Piezoelectric ceramics of the composition Na(0.5)K(0.5)NbO(3) (NKN) with grain sizes in the range of 0.2-1 mu m were fabricated by spark plasma sintering. Ferroelectric domain size decreases with decreasing grain size and non-180 degrees ferroelectric domains walls were still visible in 200 nm sized grains. The Curie point of the ceramics was grain size independent. This suggests that the critical grain size for a single domain single grain structure for NKN is <200 nm. Optimized processing conditions enabled ceramics of high densities (>99.5% theoretical density) to be made at T >= 850 degrees C. For the dense ceramics (grain size >= 350 nm), the room temperature dielectric constant and coercive field increased with decreasing grain size. The remnant polarization was grain size independent. The material sintered at 850 degrees C is a very good candidate for lead-free piezoelectric applications because of its high piezoelectric constant (d(33) = 160 +/- 2 pC/N).
17.	Gruner, Daniel, et al. (author) Direct Scanning Electron Microscopy Imaging of Ferroelectric Domains After Ion Milling 2010 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 93:1, s. 48-50 Journal article (peer-reviewed)abstract A method for directly observing the ferroelectric domain structure by scanning electron microscopy after argon ion milling has been established. Its advantages are exemplified by exposing the domain structure in three widely used ferroelectric ceramics, BaTiO3, (Na,K)NbO3, and Pb(Ti,Zr)O-3. Stable high-resolution images revealing domains with widths <30 nm have been obtained. The domain contrast is caused by electron channeling and is strongly dependent on the sample tilt angle. Owing to a strain- and defect-free surface generated by gentle ion milling, pronounced orientation contrast is observed.
18.	Guicciardi, Stefano, et al. (author) Microstructure and Toughening Mechanisms in Spark Plasma-Sintered ZrB2 Ceramics Reinforced by SiC Whiskers or SiC-Chopped Fibers 2010 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 93:8, s. 2384-2391 Journal article (peer-reviewed)abstract Starting from a ZrB2 matrix, composites containing 10, 20 vol% of SiC whiskers and 20 vol% of SiC-chopped fibers were sintered by spark plasma sintering at 1500 degrees C. The addition of whiskers allowed both strengthening (740-770 MPa) and toughening (5.1-5.7 MPa center dot m1/2) compared with the reference material. In the fiber-reinforced composite, the increase in fracture toughness (5.5 MPa center dot m1/2) was accompanied by a decrease of strength (370 MPa). Toughening mechanisms were explored through the analysis of crack propagation. Crack deflection, crack pinning, and thermal residual stresses were the most important mechanisms identified. The experimental toughness increase was successfully compared with the values predicted by theoretical models. Compared with the baseline material, the reinforced composites showed an increased strength at 1200 degrees C in air. The highest value, 450 MPa, was for the fiber-reinforced composite.
19.	Hallstedt, Bengt (author) Assessment of the CaO-Al2O3 System 1990 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 73:1, s. 15-23 Journal article (peer-reviewed)abstract A thermodynamic assessment of the quasi-binary system CaO-Al2O3 has been made using a computerized CALPHAD (calculation of phase diagrams) technique. The actual optimization was carried out with a computer program for the optimization of parameters in thermodynamic models called PARROT. The liquid phase is described by a simple two-sublattice subregular solution model with Ca2+ and Al3+ as cationic species and O2- as anionic species. All solid phases are treated as stoichiometric compounds. A consistent set of parameters describing the system is presented, and numerous comparisons with experimental data are made. There is a lack of accurate data in the high-alumina part of the system, and the importance of a better knowledge of the CaO·6Al2O3 phase is stressed.
20.	Iftekhar, Shahriar, et al. (author) Glass Formation and Structure–Property–Composition Relations of theRE2O3–Al2O3–SiO2 (RE = La, Y, Lu, Sc) Systems 2011 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 94:8, s. 2429-2435 Journal article (peer-reviewed)abstract We report the glass-forming regions of the ternary Lu2O3–Al2O3–SiO2 and Sc2O3–Al2O3–SiO2 systems. The density, molarvolume, compactness, Vickers hardness, refractive index, aswell as the glass transition (Tg) and crystallization temperatureare compared for two series of RE–Al–Si–O (RE=La, Y, Lu,Sc) glasses that display a constant molar ratio nAl/nSi=1.00,whereas nRE/nSi is equal to either 0.62 or 0.94. Several glassproperties scale roughly linearly with the cation field strength(CFS) of the rare-earth (RE3+) ion, except for the Tg values ofthe Sc-bearing glasses that are significantly lower than expected.Magic-angle spinning 29Si and 27Al nuclear magneticresonance (NMR) reveal enhanced network disorder and increasedrelative populations of AlO5 and AlO6 polyhedra in thealuminosilicate glasses for increasing RE3+ CFS, but overallsimilar Si and Al local environments (chemical shifts and quadrupolarcouplings) in all samples associated with a constant nRE/nSi ratio, except for unexpectedly shielded 29Si NMR signalsobserved from the Sc–Al–Si–O glasses.
21.	Jiang, Qing-Hui, et al. (author) Ferroic properties of highly dense multiferroic Bi1-xLa0.05TbxFeO3 ceramics via sheltered spark plasma sintering 2008 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 91:7, s. 2189-2194 Journal article (peer-reviewed)abstract Multiferroic Bi0.95-xLa0.05TbxFeO3 (BLTFO) ceramics were prepared by spark plasma sintering. The protection of CeO2 powders in the spark plasma sintering process can effectively restrain the valence fluctuation of iron ions and high-dense BLTFO ceramics with good dielectric and ferroelectric properties are fabricated. The BLTFO ceramics have low loss (tan delta similar to 5%) between 10(2) and 10(6) Hz. The doping of Tb can increase the dielectric and ferromagnetic properties, but decrease the ferroelectricity of BLTFO ceramics.
22.	Lane, Nina J, et al. (author) Comment on "Ti5Al2C3: A New Ternary Carbide Belonging to MAX Phases in the Ti-Al-C System" 2012 In: Journal of The American Ceramic Society. - : Wiley-Blackwell. - 0002-7820 .- 1551-2916. ; 95:10, s. 3352-3354 Journal article (peer-reviewed)abstract n/a
23.	Larker, Richard (author) Reaction Sintering and Properties of Silicon Oxynitride Densified by Hot Isostatic Pressing 1992 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 75:1, s. 62-66 Journal article (peer-reviewed)abstract Silicon oxynitride ceramics were reaction sintered and fully densified by hot isostatic pressing in the temperature range 1700°C to 1950°C from an equimolar mixture of silicon nitride and silica powders without additives. Conversion to Si2N2O increases steeply from a level around 5% of the crystalline phases at 1700°C to 80% at 1800°C, and increases a few percent further at higher temperatures. α-Si3N4 is the major residual crystalline phase below 1900°C. The hardness level for materials containing 85% Si2N2O is approximately 19 GPa, comparable with the hardness of Si3N4 hot isostatically pressed with 2.5 wt% Y2O3, while the fracture toughness level is around 3.1 MPa. m1/2, being approximately 0.8 MPa.m1/2 lower. The three-point bending strength increased with HIP temperature from approximately 300 to 500 MPa
24.	Lin, Yuan-Hua, et al. (author) Electrical transport properties of La2CuO4 ceramics processed by the spark plasma sintering 2007 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 90:12, s. 4005-4008 Journal article (peer-reviewed)abstract Highly dense La2CuO4 ceramics have been prepared by the spark plasma sintering technique. Temperature dependence of electrical conductivity indicates that La2CuO4 ceramics sintered at over 875 degrees C exhibit a metal-like behavior, which should be ascribed to the special La2CuO4 crystal structure and its correlation splitting of the half-filled d(x2-y2) band. Our experimental data indicate that all of the La2CuO4 samples exhibit positive thermoelectric power in the whole measuring temperature range, indicating that the majority of charge carriers are holes. It is desirable to obtain good thermoelectric performance for this system by optimizing the electrical properties and reducing the thermal conductivity.
25.	Mao, Huahai, et al. (author) Phase equilibria and thermodynamics in the Al(2)O(3)-SiO(2) system : Modeling of mullite and liquid 2005 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 88:9, s. 2544-2551 Journal article (peer-reviewed)abstract The AI(2)O(3)-SiO2 system has been reassessed using a solution model for mullite extending from sillimanite to a hypothetical state of alumina. The property of sillimanite, to be used to describe one of the end-members, was extracted from an analysis of the T-P phase diagram for AI(2)SiO(5) polymorphs. It was possible to represent the information on the range of stability of mullite, including some showing that mullite extends to higher SiO2 contents than represented by the composition of 3:2 mullite. An attempt was made to model the liquid with the ionic two-sublattice model using a new species AIO(2)(-1). The pressure dependence of AI(2)SiO(5) polymorphs was optimized by a new model recently implemented in Thermo-Cale.
26.	Mao, Huahai, et al. (author) Thermodynamic assessment of the CaO-Al2O3-SiO2 system 2006 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 89:1, s. 298-308 Journal article (peer-reviewed)abstract The CaO-Al2O3-SiO2 system has been assessed with the CALP-HAD technique, based on recent assessments of its binary systems. A new species AlO2-1 was introduced for modeling liquid Al2O3. The ternary liquid phase was described using the ionic two-sublattice model as (Al+3, Ca+2)(p) (AlO2-1, O-2, SiO4-4 SiO20)(Q). The available experimental data were critically examined and a self-consistent set of thermodynamic descriptions was obtained. Various phase diagrams and property diagrams, including isothermal sections, isoactivity lines, and a projection of the liquidus surface, are presented. Information on viscosity seems to support the use of the AlO2-1 species.
27.	Mazaheri, Mehdi, et al. (author) High-Temperature Mechanical Spectroscopy of Nitrogen-Rich Ca-alpha-SiAlON Ceramics 2011 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 94:5, s. 1536-1545 Journal article (peer-reviewed)abstract Nitrogen-rich Ca-alpha-SiAlON ceramics made with different starting powder compositions have been studied by high-temperature mechanical spectroscopy in parallel with compressive deformation in a spark plasma sintering equipment. The mechanical loss spectra measured upon heating show a relaxation peak at about 1150 K and a high-temperature exponential background at higher temperatures (> 1400 K), which are attributed to the alpha-relaxation in the glassy phase and to grain-boundary sliding, respectively. A theoretical interpretation of the results shows that the peak position is mainly a function of glass viscosity. The amplitude of the peak is not only affected by the glassy phase quantity but also depends on the restoring force due to grain elasticity. Therefore, despite a higher amount of glassy phase specimens containing elongated grains may show a lower peak. The amplitude of the internal friction peak corresponding to alpha-relaxation can be used to predict the compression creep of silicon-nitride-based ceramics.
28.	Mouzon, Johanne, et al. (author) Effect of drying and dewatering on yttria precursors with transient morphology 2006 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 89:10, s. 3094-3100 Journal article (peer-reviewed)abstract The influence of drying and dewatering of a yttrium hydroxynitrate precursor with transient morphology was investigated. The ability of this precursor to form soft agglomerated nanoparticles after calcination is dependent on the dewatering method. Freeze drying leads to finer particles than other dewatering methods that involve removal of the solvent from its liquid state. As water is directly removed by sublimation during freeze drying, this method inhibits the formation of solid bridges between hydroxynitrate platelets. These bridges, which form with the other dewatering methods, destabilize the spheroidization process of the platelets during subsequent firing at high temperatures.
29.	Mouzon, Johanne, et al. (author) Influence of agglomeration on the transparency of yttria ceramics 2008 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 91:10, s. 3380-3387 Journal article (peer-reviewed)abstract In this work, five yttria powders with slightly different states of agglomeration, inherited from various procedures of dewatering the same precursor, were densified by a combination of vacuum sintering followed by hot isostatic pressing (HIP). In order to relate the densification behavior of each powder to its state of agglomeration, all powders were characterized by tap density measurements, X-ray diffraction, nitrogen adsorption, and laser scattering, while the microstructures of the corresponding densified samples were studied by optical and scanning electron microscopy. The five yttria powders produced sintered samples that differed remarkably from each other in terms of transparency. These discrepancies were related to the degree of fineness in the powders at two different levels. At the level of primary particles, fine and weakly agglomerated powder was very sinterable, causing abnormal grain growth to occur only in the very late stage of sintering. However, the resulting entrapped pores and reduction due to vacuum sintering were responsible for poor optical properties. At the agglomerate level, a bimodal size distribution was identified for all powders. For powders showing severe agglomeration of the primary particles, increasing the relative content of the smaller size population of agglomerates was found to trigger abnormal grain-growth earlier during presintering. This was attributed to the density around large agglomerates exceeding a critical threshold in the green bodies. Finally, transparency was achieved in samples for which presintering was stopped before grain growth became abnormal. This confirmed that the key to successfully obtaining transparency was to keep porosity intergranular, which could be removed subsequently by HIP treatment.
30.	Naguib, Michael, et al. (author) On the Topotactic Transformation of Ti2AlC into a Ti-C-O-F Cubic Phase by Heating in Molten Lithium Fluoride in Air 2011 In: Journal of The American Ceramic Society. - : Wiley-Blackwell. - 0002-7820 .- 1551-2916. ; 94:12, s. 4556-4561 Journal article (peer-reviewed)abstract Herein we report on the formation of a TiCOF phase via the topotactic transformation of Ti2AlC by immersion in molten lithium fluoride, LiF, at 900 degrees C in air for 2 h. The Al diffuses out of the structure and reacts with LiF to form Li3AlF6. X-ray diffraction, Raman spectroscopy, optical, scanning and transmission electron microscopy, with energy-dispersive spectroscopy, showed the selective etching of Al from the structure and the formation of a cubic, rock-salt, TiCOF phase. The transformation is topotaxial, involves de-twinning of the hexagonal Ti2AlC structure and results in domains that are of the order of 10 nm. The reaction rate is significantly higher when the reaction is carried out in air than when it is carried out in vacuum.
31.	Ng, Jovice BoonSing, 1975-, et al. (author) Using differential scanning calorimetry to follow how gelcasting proceeds 2007 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 90:3, s. 999-1001 Journal article (peer-reviewed)abstract Differential scanning calorimetry studies on aqueous low-toxicity monomer–crosslinker gelcasting systems loaded with zirconia powder provided information on the onset and kinetics of the polymerization reaction. A simple procedure was developed to determine the relative importance of the individual components on the gelation process. It was found that the thermal stability and dissociation of the initiator control the gelation rate and that the zirconia particles accelerate the gelation.
32.	Niska, John, et al. (author) Effect of oxygen loss on densification when hot isostatic pressing YBa2Cu3O7-δ 1989 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 72:8, s. 1508-1510 Journal article (peer-reviewed)abstract Hot isostatic pressing of the high-Tc superconductor YBa2Cu3O7-δ can lead to loss of oxygen and transformation of the material from the high-Tc orthorhombic phase to the nonsuperconducting tetragonal phase. It is shown that glass encapsulation helps retain the orthorhombic structure, whereas steel encapsulation resulted in formation of the tetragonal phase. Reasons for this phenomenon are discussed. The equilibrium oxygen gas pressure for the oxygen decomposition reaction in YBa2Cu3O7, however, prevents full densification of this material in glass when employing hot isostatic pressing conditions of 200 MPa and 845°C.
33.	Nordberg, Lars-Olov, et al. (author) Stability and oxidation properties of RE–α-Sialon ceramics (RE = Y, Nd, Sm, Yb) 1998 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 81:6, s. 1461-1470 Journal article (peer-reviewed)abstract Oxidation studies of hot-pressed RE–α-sialons, REx-Si12−4.5xAl4.5xO1.5xN16−1.5x (with x = 0.40 for RE = Nd, Sm,Yb; and x = 0.48 for RE = Y) were carried out in oxygen in a TG apparatus for ca. 20 h. Very good oxidation resistance was found for the Yb-doped samples, with parabolic rateconstants Kp ≈ 0.09 × 10−6–3 × 10−6 mg2 cm−4 s−1 in the temperature range 1250–1350°C. The promising performance of this material was corroborated by long-term oxidation experiments (5 days) in air at 1350°C. Although the oxidation kinetics can be described by simple equations related to the parabolic rate law (e.g., the arctan equation, ΔW/Ao = α·arctan(bt)½+ct½), the oxidation process in these materials is likely to be complex. The significantly lower oxidation resistance of the RE = Nd, Sm doped α-sialons, especially at higher temperatures, is related to the formation of melilite, RE2Si3−yAlyO3+yN4−y (y ≈ 1), in these systems. The melilite phase is also responsible for the thermal instability of the Nd– and Sm–α-sialons.
34.	Nunez-Gonzalez, Beatriz, et al. (author) Improvement of the Spark-Plasma-Sintering Kinetics of ZrC by High-Energy Ball-Milling 2012 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 95:2, s. 453-456 Journal article (peer-reviewed)abstract The effect of the duration of high-energy ball-milling on the spark-plasma sintering (SPS) kinetics of additive-free ZrC ultra-high-temperature ceramics (UHTCs) was investigated. It was found that the crystallite size of ZrC is refined progressively from the as-purchased condition down to a few nanometers with increasing high-energy ball-milling time, and that this crystallite size refinement progressively enhances the SPS kinetics, reducing the characteristic temperatures of the sintering process. While this enhancement was found to be only moderate with the refinement to the ultra-fine range, it was highly marked with the refinement to the nanometer range. Implications for the lower-temperature processing of ZrC UHTCs are discussed.
35.	Pahari, Bholanath, et al. (author) Composition-property-structure correlations of scandium aluminosilicate glasses revealed by multinuclear 45Sc, 27Al and 29Si solid-state NMR 2012 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 95:8, s. 2545-1553 Journal article (peer-reviewed)abstract Many features of aluminosilicate glasses incorporating a rare-earth (RE) ion are dictated by its mass and cation field strength (CFS). ScAlSiO glasses are interesting because Sc3+ exhibits the highest CFS but the lowest mass of all RE3+ ions. We explore relationships between the glass composition and several physical properties, such as density, glass-transition temperature (Tg), Vickers hardness, and refractive index, over the glass forming region of the ternary Sc2O3Al2O3SiO2 system. The glasses exhibit uniform and unexpectedly low Tg-values (similar to 875 degrees C), but a high microhardness (approximate to 9.3 GPa) that correlates with the Sc2O3 content. 29Si magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy shows enhanced deshielding and a minor glass-network ordering as either the Al or Sc content of the glass increases. 27Al MAS NMR reveals that besides the expected AlO4 tetrahedra, substantial amounts of AlO5 (31%35%) and AlO6 (approximate to 5%) polyhedra are present in all ScAlSiO glass structures. 45Sc isotropic chemical shifts (similar to 92 ppm) derived from MAS and 3QMAS (triple-quantum MAS) NMR experiments are consistent with ScO6 environments.
36.	Persson, Jeanette, et al. (author) Interpretation of the Parabolic and Non-Parabolic Oxidation Behaviour of Silicon Oxynitride 1992 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 75:12, s. 3377-3384 Journal article (peer-reviewed)abstract The oxidation process of Si2N2O, prepared by a hot isostatic pressing technique, has been studied by the thermogravimetric method. The oxidation has been performed in oxygen for 20 h in the temperature range 1300° to 1600°C, producing oxide scales of amorphous SiO2 and α-cristobalite. The weight gain for T 1350°C does not begin to follow a parabolic rate law, until a certain time, t0. The A0 parameter in the parabolic rate law, (Δw/A0)2=Kpt+B, represents the cross section area, A, through which the oxygen diffuses; in the derivation of this law A is assumed to be constant during the experiment. If crystallization occurs during the oxidation process, A will decrease with time. A function, A(t), describing the time dependence, has been developed and incorporated into the parabolic rate law, yielding a new rate law, which reads ΔW/A0=a arctan √bt+c√t. This new rate law is valid in the time interval t < t0, whereas, for t > t0, the oxidation process follows the equation (Δw/A0)2=K°pt+B0. The relation of the latter equation to the common parabolic rate law is described. All of the oxidation curves are described by these equations. The activation energy of the oxygen diffusion (and of the oxidation (Kp)) is found to be 245 ± 25 kJ/mol, which is consistent with literature values reported for oxygen diffusion.
37.	Pohl, Annika, et al. (author) Alkoxide Route to La0.5Sr0.5CoO3 Films and Powders 2005 In: Journal of the American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 88:8, s. 2099-2105 Journal article (peer-reviewed)abstract An all-alkoxide route to films and nano-phase powders of the La0.5Sr0.5CoO3 perovskite is described. To our knowledge, this is the first purely alkoxide-based route to (La1xSrx)CoO3, and it yields phase-pure and elementally homogeneous perovskite at 700°C by heating at 2°C/min. At 700°C, a cubic unit cell was obtained with ac=3.853Å, and after further heating to 1000°C, a rhombohedral cell could be indexed: ar=5.417 Å, r=59.94°. Ninety to 130 nm thick films of La0.5Sr0.5CoO3 were obtained by spin coating. The gel-to-oxide conversion was studied in some detail, using thermo-gravimetric analysis, differential scanning calorimetry, powder X-ray diffraction, IR spectroscopy, and transmission electron microscope equipped with an energy-dispersive X-ray spectrometer.
38.	Prakash, Braham, et al. (author) Friction coefficient of (a+b)-SiAlON composite against a steel and dense silicon nitride Tribopair 1999 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 82:8, s. 2255-2256 Journal article (peer-reviewed)abstract The friction characteristics of hot-pressed (α+β)-SiAlON, versus those of bearing steel and dense Si3N4 under dry sliding conditions, are reported. The coefficient of friction decreases as the alpha-SiAlON content increases and is double that of a metal-ceramic pair, in comparison to that of a ceramic-ceramic pair.
39.	Shen, Zhijan, et al. (author) Melilite Formation in a Samarium-Stabilized alpha-Sialon Ceramic during Postsintering Heat Treatments 1997 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 80:3, s. 817-821 Journal article (peer-reviewed)abstract The formation of the melilite solid solution phase (M), Sm2Si3-xAlxO3xN4-x, in an alpha-sialon sample of overall composition Sm0.6Si9.28Al2.69O1.36N14.76, was studied as a function of time in the temperature interval 13751525C. The alpha-sialon ceramic contained only minor amounts of the 21R sialon polytype and some residual grain-boundary glass before heat treatment. In situ studies by high-temperature X-ray diffraction were combined with postsintering heat treatment followed by quenching. The M-phase was found to be formed by two different mechanisms: either crystallization of the residual grain-boundary liquid or a direct decomposition of the alpha-sialon phase. The liquid crystallized during the first 1015 min of heat treatment, yielding a rapid M-phase formation, and further formation of M-phase continued at a much slower rate, related to the decomposition of alpha-sialon
40.	Shen, Zhijian, et al. (author) Rapid formation and deformation of Li-doped sialon ceramics 2004 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 87:4, s. 727-729 Journal article (peer-reviewed)abstract Two lithium-doped sialon ceramics were densified and superplastically deformed by spark plasma sintering (SPS). Rapid densification with linear shrinkage rates of approximately 5 × 10−3 s−1 were observed for samples heated at a rate of 100°C/min up to ∼1400°C under a uniaxial pressure of 40 MPa. Isothermal deformation by SPS-preprepared, fully densified ceramics performed at T≥ 1450°C yielded strain rates in the order of 10−2 s−2. It is suggested that a high heating rate promotes material transport via formation of a nonequilibrated oxygen-rich liquid of low viscosity. This finding most likely holds true for other liquid-phase sintered ceramics as well and has implications for cost-effective manufacturing of ceramic components.
41.	Spencer, C B, et al. (author) Phase Evaluation in Al(2)O(3) Fiber-Reinforced Ti(2)AlC During Sintering in the 1300 degrees C-1500 degrees C Temperature Range 2011 In: Journal of The American Ceramic Society. - : Wiley-Blackwell. - 0002-7820 .- 1551-2916. ; 94:10, s. 3327-3334 Journal article (peer-reviewed)abstract In this article, the reactivity of Ti(2)AlC powders, with 3 and 10 mu m alumina, Al(2)O(3), fibers during pressure-assisted sintering is explored. Samples were fabricated by hot-isostatic-pressing (HIPed) or hot-pressing (HPed), and characterized by X-ray diffraction, differential thermal analysis, and electron microscopy-both scanning and transmission-equipped with energy dispersive X-ray spectroscopes. Samples prepared at 1300 degrees C were fully dense, with no apparent reaction between fiber and matrix. In samples HPed to 1500 degrees C, even pure Ti(2)AlC powders dissociated to Ti(3)AlC(2) according to: 2 Ti(2)AlC = Ti(3)AlC(2) + TiAl(x) (l) + (1-x) Al (l/v), with x andlt; 1. More severe Al loss results in the formation of TiC(y). The presence of the Al(2)O(3) fibers delayed densification enough to allow most of the Al and some of the Ti to escape into the vacuum of the hot press or react with the encapsulating glass during HIPing a resulting in a more intensive dissociation of the Ti(2)AlC. Although, in principle Ti(2)AlC can be reinforced with Al(2)O(3) fibers, the processing/use temperature will have to be kept below 1500 degrees C, as, at that temperature the fibers, used here, sinter together.
42.	Sugunan, Abhilash, et al. (author) Radially Oriented ZnO Nanowires on Flexible Poly-L-Lactide Nanofibers for Continuous-Flow Photocatalytic Water Purification 2010 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 93:11, s. 3740-3744 Journal article (peer-reviewed)abstract Several oxide ceramics, notably ZnO and TiO2 are known to catalyze decomposition of organic molecules in water under ultraviolet (UV) irradiation. Here we describe fabrication of highly flexible ZnO-based hierarchical nanostructure obtained by growing radially oriented ZnO nanowires on poly-L-lactide nanofibers. Utilizing the flexibility and high surface area of polymeric nanofibers as novel substrate for growth of the photochemically active ZnO nanowires we show a proof-of-principle demonstration of a continuous flow water treatment setup. We have monitored photocatalytic decomposition of known organic pollutants, such as methylene blue, monocrotophos, and diphenylamine under illumination with UV light using this highly flexible hierarchical nanostructure.
43.	Wang, Jing, et al. (author) Substrate effect on the magnetoelectric behavior of Pb(Zr0.52Ti0.48)O3 film-On-CoFe2O4 bulk ceramic composites prepared by direct solution spin coating 2009 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 92:11, s. 2654-2660 Journal article (peer-reviewed)abstract Magnetoelectric (ME) composite structures of Pb(Zr0.52Ti0.48)O3 (PZT) and CoFe2O4 (CFO) were prepared by directly growing PZT films on highly dense CFO ceramics via a simple solution spin coating, rather than by conventional high-temperature cofiring. An obvious ME response, which had the same bias-dependent trend as the piezomagnetic coefficient of CFO ceramics, was observed in such film-on-bulk ceramic composites. It was found that the PZT films showed a good ferroelectric feature, and the ME response of the composites strongly depended on the resistivity of the CFO ceramics as both a substrate and a bottom electrode. The results suggest plenty of room for further enhancing the ME response of such films-on-ceramic substrate composites.
44.	Wittmer, M., et al. (author) Mechanical properties of liquid-phase-bonded copper-ceramic substrates. 1982 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 65:3, s. 149-153 Journal article (peer-reviewed)abstract Liquid-phase bonding of copper foils to ceramic substrates is a very attractive technique for the fabrication of metallized substrates for hybrid power electronics applications. The design and reliability considerations of such substrates necessitate the knowledge of their mechanical properties. Therefore, stresses and strains in the copper and in the ceramic of bonded substrates were investigated. Theoretical calculations are presented to support the experimental results.
45.	Xiong, Yan, et al. (author) Preparation of Transparent Nanoceramics by Suppressing Pore Coalescence 2011 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 94:12, s. 4269-4273 Journal article (peer-reviewed)abstract Microstructural developments in nanoceramics were investigated in 3Y-TZP compacts with relative density (RD) exceeding 93%. Special attentions were paid to the evolutions of pore structures. It was found that the densification process of nanoceramic compacts with apparently close porosity was greatly jeopardized by pore coalescence. This observation was interpreted by the coalescence of locally interconnected pores originated from inhomogeneous packing of particles. The pore coalescence can be suppressed by application of an external pressure. The processing principle was demonstrated by spark plasma sintering (SPS) with extended holding at a minimized sintering temperature. The highly dense 3Y-TZP nanoceramics containing no large pores became optically transparent.
46.	Yoon, Songhak, et al. (author) Electronic Conduction Mechanisms in BaTiO3-Ni Composites with Ultrafine Microstructure Obtained by Spark Plasma Sintering 2010 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 93:12, s. 4075-4080 Journal article (peer-reviewed)abstract Spark plasma sintering (SPS) was used to densify BaTiO3-Ni composite powders to relative densities above 92.8%. With the increasing Ni content, a decrease in relative density is observed, suggesting that Ni hampers the consolidation process. The microstructures of the BaTiO3-Ni composites were of duplex character. The crystallite size of the BaTiO3-grains was around 100 nm in average. The ceramic matrix phase of BaTiO3 surrounded Ni inclusions of approximately 1 mu m in diameter that were completely incorporated without the formation of any elongated metallic filaments. The ac conductivity of these BaTiO3-Ni composites increased with increasing Ni content and with temperature. The dominant conduction mechanisms in SPSed BaTiO3-Ni composites showed quite a complicated behavior. A gradual change from band conduction of trapped electrons in oxygen vacancies to a hopping-type motion of small polarons between Ti4+ and Ti3+ is suggested to occur, when the Ni content increases. The influence of oxygen vacancies and other lattice defects on the electrical properties of BaTiO3-Ni composites is discussed.
47.	Yu, H., et al. (author) Thermodynamic assessment of the lithium-borate system 2000 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 83:12, s. 3082-3088 Journal article (peer-reviewed)abstract The Li2O-B2O3 quasi-binary system is assessed. A two-sublattice ionic solution model, (Li1+)(P)(O2-, BO33-, B4O72-, B3O4.5)(Q), is adopted to describe the liquid phase, All solid phases are treated as stoichiometric compounds. A set of parameters consistent with most of the available experimental data on phase diagram and thermodynamic properties is obtained by using the CALPHAD technique.
48.	Zhou, L. J., et al. (author) Electric fatigue in antiferroelectric lead zirconate stannate titanate ceramics prepared by spark plasma sintering 2005 In: Journal of The American Ceramic Society. - : American Ceramic Society. - 0002-7820 .- 1551-2916. ; 88:10, s. 2952-2954 Journal article (peer-reviewed)abstract The fatigue behavior of lead zirconate stannate titanate (PZST) ceramics prepared by spark plasma sintering (SPS) was investigated. Polarization and strain hysteresis loops were monitored. The material shows a high resistance to fatigue because of bipolar electric cycling. Both maximum strain and switchable polarization first show a fatigue stage 0 to 10(5) cycles and then a fatigue-free period up to 10(8) cycles. The maximum losses of maximum strain and switchable polarization are 18% and 10% of their initial values, respectively. The dominant fatigue mechanism is assigned to the pinning of domain walls by charged defects.
49.	Zhou, L. J., et al. (author) Electric fatigue in ferroelectric lead zirconate stannate titanate ceramics prepared by spark plasma sintering 2006 In: Journal of The American Ceramic Society. - : Wiley. - 0002-7820 .- 1551-2916. ; 89:12, s. 3868-3870 Journal article (peer-reviewed)abstract Ferroelectric lead zirconate stannate titanate ceramics were prepared by spark plasma sintering (SPS). Compared with its counterpart densified by conventional sintering (CS), the SPS material shows a smaller remanent polarization and maximum strain as well as a higher coercive field. Electric fatigue in both materials was investigated. In contrast to CS samples, the SPS specimens show a lower resistance to bipolar electric cycling, characterized by a faster decrease in remanent polarization and maximum strain at cycle number below 10(6.5) and a subsequent slower reduction of the properties at high cycle numbers up to 10(8).
50.	Zhou, L. J., et al. (author) Preparation and properties of lead zirconate stannate titanate sintered by spark plasma sintering 2004 In: Journal of The American Ceramic Society. - : American Ceramic Society. - 0002-7820 .- 1551-2916. ; 87:4, s. 606-611 Journal article (peer-reviewed)abstract Lanthanum-doped lead zirconate stannate titanate ceramics were successfully compacted to full density by spark plasma sintering (SPS). SPS samples densified at 900degrees or 950degreesC exhibit nearly full density and fine grain size (about 300 nm). Compared with samples from conventional sintering (CS), SPS samples show larger permittivity accompanied by a deterioration in dielectric loss and special strain hysteresis loops similar to those of ferroelectric relaxors, with a diffuse AFE-FE phase transition and less field-induced longitudinal strain. The differences in the properties of SPS and CS materials are attributed to the variations of the resultant microstructures, especially the grain size, of the ceramics.

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