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1.	Mukerji, Joydeb, et al. (författare) Wear of Nitrogen Ceramics and Composites in contact with Bearing Steel under Oscillating Sliding Conditions 1998 Ingår i: Ceramics International. - 0272-8842 .- 1873-3956. ; 24:1, s. 19-24 Tidskriftsartikel (refereegranskat)abstract The wear of nitrogen based ceramics in contact with bearing steel balls (SAE 52100) was investigated under reciprocating sliding conditions at a velocity of 0.1 m/s, and 20 N, 40 N and 100 N load. Three types of ceramics were studied: viz. hot pressed silicon nitride (HPSN) sintered with selected liquid in the system yttria-aluminium nitride-silica and composites of HPSN with BN and TiC; SiAlON formulated with different amounts of alumina and silica; and aluminatitanium nitride composite having 60 mol% TiN. Among the HPSN composites, HPSN 15vol% TiC had the lowest average wear factor (K) of 2.0 × 10- 5mm3/m/ N. The SiAlONs, in general, had the highest K and this increased with increasing O concentration. The lowest K value for SiAlON ceramic was 6.9 × 10-5mm3/m/N. The high K value of SiAlON is attributed to O substitution, which promotes adhesive wear resulting in mutual material transfer. The lowest wear of all the ceramics tested was found for the alumina-titanium nitride composite, the wear factor being of the order of 4.4 × 10-7mm3/m/N, which is one order of magnitude lower than the other nitrogen ceramics. In the case of HPSN and alumina-titanium nitride composites, abrasive wear and wear due to microfracture were the main wear mechanisms. Wear of the steel ball was lowest when in contact with HPSN---TiC composites, being almost equal to that of the ceramic, whereas the alumina-titanium nitride composite wore away the steel almost 20 times faster than the ceramic and will thus be unsuitable as a counterface material for 52100 steel.
2.	Afroze, Shammya, 1987, et al. (författare) Structure-conductivity relationship of PrBaMnMoO 6-δ through in-situ measurements: A neutron diffraction study 2021 Ingår i: Ceramics International. - : Elsevier BV. - 0272-8842 .- 1873-3956. ; 47:1, s. 541-546 Tidskriftsartikel (refereegranskat)abstract The structural and electrochemical properties of the double perovskite-type oxide, PrBaMnMoO6-δ, was investigated using neutron diffraction with in-situ conductivity measurement under a dry Argon atmosphere from 25 °C to 700 °C. A Rietveld refinement of the neutron diffraction data confirmed monoclinic symmetry in the P21/n space group. Rietveld refinement also confirms the unit cell parameters of a = 5.6567 (1) Å, b = 5.6065 (2) Å, c = 7.9344 (1) Å and β = 84.43° with reliable atomic positions and refinement factors (R-factors). Neutron diffraction data refinement shows two minor phases (<5%), an orthorhombic AB2O5 type phase of PrMn2O5 in the Pbam (No. 32) space group with unit cell parameters, a = 7.9672 (1) Å, b = 8.9043 (2) Å and c = 5.8540 (1) Å and a scheelite phase of BaMoO4 in the tetragonal I41/a (88) space group with the unit cell parameters, a = b = 5.9522 (1) Å, and c = 12.3211 (2) Å. Morphological images revealed a porous and intertwined microstructure. In-situ conductivity measurement shows that the total conductivity of this material was 130.84 Scm−1 at 700 °C.
3.	Aleni, Afshin H., et al. (författare) 3D printing of dense and porous TiO2 structures 2020 Ingår i: Ceramics International. - : Elsevier. - 0272-8842 .- 1873-3956. ; 46:10, s. 16725-16732 Tidskriftsartikel (refereegranskat)abstract Direct foam writing allows the fabrication of highly porous and hierarchical ceramic structures with high specific mechanical properties. This manufacturing technique, however, has mainly used stabilized Al2O3 foam inks. In this work, we pressent a novel foam ink based on TiO2. This ink uses polyvinyl alcohol (PVA) as a binder and a small amount of zinc as a frothing agent. We used this ink to produce cylindrical foam samples via direct foam writing. The foams had a porosity of up to 65% and a mean pore size of 180 μm, which is significantly larger than previously reported for direct foam writing with Al2O3. The foams were tested in compression and were found to have an elastic modulus of 0.5 GPa and a compressive strength of 12–18 MPa. These mechanical properties are similar to those of porous ceramics produced by conventional manufacturing routes. Therefore, this work represents a step forward by broadening the direct foam writing process to a wider range of porous ceramics.
4.	Ali, Amjad, et al. (författare) A potential electrolyte (Ce1-x CaxO2-delta) for fuel cells:Theoretical andexperimental study 2018 Ingår i: Ceramics International. - : ELSEVIER SCI LTD. - 0272-8842 .- 1873-3956. ; 44:11, s. 12676-12683 Tidskriftsartikel (refereegranskat)abstract First-principles calculations are performed using density function theory to explore the effects of dopant Ca in ceria (Ce1-x CaxO2-delta). The impact of oxygen vacancy on band gap and density of states is examined in doped ceria using generalized gradient approximations. Vacancy association and vacancy formation energies of the doped ceria are calculated to reveal the effect of dopant on ion conduction. The experimental study of the sample Ce0.875Ca0.125O2-delta) was performed to compare with the theoretical results. The obtained results from theoretical calculation and experimental techniques show that oxygen vacancy increases the volume, lattice constant (5.47315 angstrom) but decrease the band gap (1.72 eV) and bulk modulus. The dopant radius (1.173 angstrom) and lattice constant (5.4718 angstrom) are also calculated by equations which is close to the DFT lattice parameter. The result shows that oxygen vacancy shifts the density of states to lower energy region. Band gap is decreased due to shifting of valence states to conduction band. Vacancy formation shows a significance increase in density of states near the Fermi level. Density of states at Fermi level is proportional to the conductivity, so an increase in density of states near the Fermi level increases the conductivity. The experimental measured ionic conductivity is found to 0.095 S cm(-1) at 600 degrees C. The microstructural studies is also reported in this work.
5.	Ali, Sharafat, 1976-, et al. (författare) Issues associated with the development of transparent oxynitride glasses 2015 Ingår i: Ceramics International. - : Elsevier. - 0272-8842 .- 1873-3956. ; 41:3, s. 3345-3354 Tidskriftsartikel (refereegranskat)abstract Oxynitride glasses and glass ceramics are increasingly recognized as potential materials in specialist applications in modern industrial sectors. Oxynitride glasses have superior mechanical, rheological and optical properties to their oxide glass counterparts. Properties of these glasses can be tailored by changes in nitrogen content and additions of various alkaline-earth and or rare-earth elements. In contrast to oxide glasses, oxynitride glasses are difficult to prepare which adds to production costs. Furthermore, they contain impurities in the form of elemental silicon and silicides, have poor oxidation resistance in air above their glass transition temperatures and have poor transparency in the visible region. This article reviews the above issues in relation to the potential applications of these glasses.
6.	Alsalmah, Hessa A., et al. (författare) Optical, conductivity, dielectric, and magnetic properties of polymer nanocomposite based on PAM/cs matrix and ZnFe2O4 NPs for use in magneto-electronic and energy storage capacitor devices 2024 Ingår i: Ceramics International. - : ELSEVIER SCI LTD. - 0272-8842 .- 1873-3956. ; 50:7, s. 12167-12174 Tidskriftsartikel (refereegranskat)abstract In this study, a cast synthesis approach was used to create flexible nanocomposite films made of polyacrylamide (PAM), chitosan (Cs), and zinc ferrite nanoparticles (ZnFe2O4 NPs). XRD analysis was used to examine the composite structure. They demonstrated the effective interaction between ZnFe2O4 NPs and PAM/Cs blend. As the concentration of nanomaterial in the host polymer matrix grew, it was observed that the PAM/Cs matrix's direct and indirect energy band gaps decreased while its absorbance of ultraviolet-visible radiations increased. The nanocomposite's AC conductivity was significantly higher than that of the blend, and 2.5 wt percent of the nanocomposite showed the highest electrical conductivity. It was observed that as frequency raised, the epsilon ' and epsilon '' declined though the concentration of nanoparticles enhanced these characteristics. Because of the high dielectric permittivity of ZnFe2O4, the values of epsilon ' and epsilon '' raised as ZnFe2O4 were higher. The outcome of the vibrating sample magnetometer (VSM) demonstrated the ferromagnetic property of the produced nanocomposites. Furthermore, the VSM study shows that as the nanoparticles content increases, the PAM/Cs/ZnFe2O4 nanocomposites' Ms, Hc, and Mr also increase. These PAM/Cs/ZnFe2O4 films were shown by the experimental results to be promising candidates for bandgap-regulated materials, electromagnetic interference shielders, frequency tunable nanodielectric, and flexible dielectric substrates for future microelectronic, optoelectronic technologies, and capacitive energy storage.
7.	Antti, Marta-Lena, et al. (författare) Phase reactions in a hot pressed TiC/Si powder mixture 2012 Ingår i: Ceramics International. - : Elsevier BV. - 0272-8842 .- 1873-3956. ; 38:3, s. 1999-2003 Tidskriftsartikel (refereegranskat)abstract This work investigated the possibility of producing dense Ti3SiC2 by hot pressing TiC/Si powders. A hot press with graphite heating elements was used for densification and the phase reactions of some hot pressed samples were further evaluated by pressureless heating in a dilatometer. The density and phase composition of the heat treated samples were evaluated using Archimedes principle and by x-ray diffractometry respectively. Hot pressing resulted in a low Ti3SiC2 yield; the main phases were TiC and TiSi2 regardless of starting powder composition, temperature, holding time or pressure. A second heating without pressure resulted in Ti3SiC2 formation, but only in samples initially hot pressed at 1300 °C or lower. At higher hot pressing temperatures, thin oxide layers on particle surfaces were locked into the structure. Acting as diffusion barriers, they prevented the Ti3SiC2 forming reaction. In hot pressed samples the density was significantly higher than in samples sintered without pressure.
8.	Archana, M. S., et al. (författare) Influence of applied pressure during field-assisted sintering of Ti(C,N)-WC-FeAl based nanocomposite 2015 Ingår i: Ceramics International. - 0272-8842 .- 1873-3956. ; 41:2, s. 1986-1993 Tidskriftsartikel (refereegranskat)abstract Ti(C,N)-WC-FeAl based nanocomposites are processed by field-assisted sintering at 1500 degrees C. The phase and microstructural evolution during the process under the influence of different applied pressures of 30, 50 and 100 MPa are studied using x-ray diffraction and scanning electron microscopy. Lattice parameters of (Ti,W)(C,N) solid solution and binder phases after sintering are found to vary with applied pressure. The nanocomposite grains are observed to possess a core-rim microstructure. Microstructural variations in terms of type, size and fraction of "corerim" structure as a function of applied pressure are investigated. The hardness and indentation fracture toughness values are in the range of 17.6-18.4 GPa and 5.9-6.8 MPa root m, respectively. These values are comparable with those reported for Ti(C,N)-based composites with metal binder. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
9.	Barick, P., et al. (författare) Effect of concentration and molecular weight of polyethylenimine on zeta potential, isoelectric point of nanocrystalline silicon carbide in aqueous and ethanol medium 2015 Ingår i: Ceramics International. - : Elsevier Ltd. - 0272-8842 .- 1873-3956. ; 41:3, s. 4289-4293 Tidskriftsartikel (refereegranskat)abstract The effect of dispersant concentration and its molecular weight on zeta potential of nanocrystalline silicon carbide in an aqueous medium was investigated. An increase in the concentration of the dispersant, such as polyethylenimine (PEI), in slurry prepared from nanosized silicon carbide, was found to augment the iso-electric point and zeta potential. However, the zeta potential was observed to decline as the pH of the slurry shifts towards the basic region. This aforementioned behavior is attributed to the enhanced mutual repulsion between the polymer chains of the dispersant adsorbed on the surfaces of SiC particles and those approaching the surfaces. The higher ionization potential of polymers in the acidic region compared to the basic region increases the adsorption. The relationship between zeta potential and pH is however, noted to remain virtually unchanged with molecular weight of PEI. Further, it is observed that zeta potential of SiC decreases with the increase in solid content of the slurry. Rheology study reveals that the ethanol based slurry has a lower viscosity than the water based slurry, making ethanol the preferred dispersing medium for colloidal processing of nanometric SiC powder. © 2014 Elsevier Ltd and Techna Group S.r.l.
10.	Barick, Prasenjit, et al. (författare) Effect of pressure and temperature on densification, microstructure and mechanical properties of spark plasma sintered silicon carbide processed with β-silicon carbide nanopowder and sintering additives 2016 Ingår i: Ceramics International. - : Elsevier BV. - 0272-8842 .- 1873-3956. ; 42:3, s. 3836-3848 Tidskriftsartikel (refereegranskat)abstract The effects of applied pressure and temperature during spark plasma sintering (SPS) of additive-containing nanocrystalline silicon carbide on its densification, microstructure, and mechanical properties have been investigated. Both relative density and grain size are found to increase with temperature. Furthermore, with increase in pressure at constant temperature, the relative density improves significantly, whereas the grain size decreases. Reasonably high relative density (~96%) is achieved on carrying out SPS at 1300 °C under applied pressure of 75 MPa for 5 min, with a maximum of ~97.7% at 1500 °C under 50 MPa for 5 min. TEM studies have shown the presence of an amorphous phase at grain boundaries and triple points, which confirms the formation of liquid phase during sintering and its significant contribution to densification of SiC at relatively lower temperatures (≤1400 °C). The relative density decreases on raising the SPS temperature beyond 1500 °C, probably due to pores caused by vaporization of the liquid phase. Whereas β-SiC is observed in the microstructures for SPS carried out at temperatures ≤1500 °C, α-SiC evolves and its volume fraction increases with further increase in SPS temperatures. Both hardness and Young׳s modulus increase with increase in relative density, whereas indentation fracture toughness appears to be higher in case of two-phase microstructure containing α and β-SiC.
11.	Batool, S S., et al. (författare) Investigation of dielectric relaxation behavior of electrospun titanium dioxide nanofibers using temperature dependent impedance spectroscopy 2013 Ingår i: Ceramics International. - : Elsevier. - 0272-8842 .- 1873-3956. ; 39:2, s. 1775-1783 Tidskriftsartikel (refereegranskat)abstract The electrospinning method has been utilized in the fabrication of titanium dioxide nanofibers (TNFs) with an average diameter of similar to 50 nm and length of 100 um. Effect of temperature on the dielectric relaxation behavior of the fabricated nanofibers have been studied using AC impedance spectroscopy. The morphological, structural and compositional aspects as well as the optical properties of the TNFs have been investigated by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive x-ray spectroscopy (EDX) and ultraviolet visible (UV vis) absorption spectrum. The permittivity behavior of the device at the frequency below 10(2) Hz shows the relaxation contribution along with the electrode polarization. Dielectric loss peak in loss tangent also confirms the presence of relaxing dipoles in TNFs. The AC conductance as a function of frequency confirms the semiconducting nature of TNFs and obeys Jonschers power law except a small deviation in the low frequency region. DC conductivity increases with increase in temperature.
12.	Berg, Camilla, et al. (författare) Bulk nanobubbles as soft templates in the fabrication of inorganic core-shell particles 2023 Ingår i: Ceramics International. - : Elsevier. - 0272-8842 .- 1873-3956. ; 49:11, s. 16501-16513 Forskningsöversikt (refereegranskat)abstract Hollow microstructured-and nanostructured-materials (also known as core-shell particles) have got great attention as advanced materials due to their fascinating physicochemical properties and favourable application prospects in many fields. In recent years, a variety of synthesis strategies have been explored to fabricate core-shell particles with different morphologies, compositions, microstructures, and thereby versatile functionalities. Among the synthesis strategies, soft-templating with the usage of nanobubbles is a feasible and effective one. Many inorganic core-shell particles have been prepared by using nanobubbles as a template. Nevertheless, studies in this field have not been reviewed comprehensively yet. Herein, the paper firstly reviewed several critical aspects of nanobubbles, such as the formation methods, stability and stabilization strategies of nano-bubbles; Secondly, characteristics of core-shell particles prepared by using nanobubbles soft template were summarized, including formation mechanisms, morphologies, etc.; Lastly, concerns regarding nanobubbles as soft templates were also briefly discussed.
13.	Berg, Camilla, et al. (författare) Electron microscopy evaluation of mineralization on peritubular dentin with amorphous calcium magnesium phosphate microspheres 2020 Ingår i: Ceramics International. - : Elsevier BV. - 0272-8842 .- 1873-3956. ; 46:11, s. 19469-19475 Tidskriftsartikel (refereegranskat)abstract Dentin hypersensitivity can be reduced by the use of a remineralization agent to hinder movement of fluids within the dentin tubules. Penetration of particles into the tubules and a continuous release of Ca2+ and phosphate ions can induce the mineralization of a material mimicking the mineral component of dentin, sealing the tubules. In this work, we have used complementary electron microscopy techniques to investigate the ultrastructure of dentin and crystallization and occlusion effects when using amorphous calcium magnesium phosphate (ACMP) microspheres on extracted human molars. Application of the particles in a gel intended for athome use resulted in intra-tubular mineralization of a carbonate substituted hydroxyapatite (HA). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed that crystallization was initiated on the peritubular dentin (PTD) with undirected crystal growth leading to the formation of a porous material. We additionally investigated the effects from using a fluoride toothpaste to potentially improve the remineralization and anti-cariogenic properties of the ACMP microspheres. Energy dispersive x-ray spectroscopy (EDX) using TEM in scanning mode (STEM) showed that fluoride incorporation resulted in an increase in aspect ratio of the crystals, crystal growth directed towards the center of the tubule lumen and densification of the mineralized material. Thus, ACMP microspheres are promising alternatives as occluding agents and the efficacy of the particles could be further improved with the complementary use of a fluoride toothpaste.
14.	Berg, Camilla, et al. (författare) Ion substitution induced formation of spherical ceramic particles 2019 Ingår i: Ceramics International. - : ELSEVIER SCI LTD. - 0272-8842 .- 1873-3956. ; 45:8, s. 10385-10393 Tidskriftsartikel (refereegranskat)abstract How to precipitate ceramic nano- and microspheres in water based solutions only using inorganic ions is a challenge. In this study, spherical particles of alkaline earth phosphates and fluorides were synthesized using a precipitation reaction. Substituting ions, through inhibition of crystal growth, was used to induce sphere formation and to alter the morphology, size and composition of the spheres. The difference in ionic radius between the substituting ion (Mg, Ca and Sr) and the main cation (Sr and Ba) influenced the critical concentration to allow for sphere formation as well as the crystallinity. The larger difference, the lower was the concentration needed to form spheres. Low concentrations of Mg was enough to generate amorphous spheres of Sr- and Ba- phosphates whereas higher concentrations were needed if the radius difference were smaller. An increasing degree of substitution leads to a decrease in crystallinity of precipitated particles. The degree of substitution was determined to 16-55% where a low degree of ion substitution in the phosphates resulted in the formation of spheres (500-800 nm) with rough surfaces composed of apatite like phases. A higher degree of substitution resulted in amorphous spheres (500 nm- (1) mu m) with smooth surfaces.
15.	Bhatti, Muhammad Ali, et al. (författare) Efficient photo catalysts based on silver doped ZnO nanorods for the photo degradation of methyl orange 2019 Ingår i: Ceramics International. - Oxford : Elsevier. - 0272-8842 .- 1873-3956. ; 45:17, Part B, s. 23289-23297 Tidskriftsartikel (refereegranskat)abstract In this study, the doped ZnO nanorods with silver (Ag) as photosensitive material are prepared by the solvothermal method. The structural and optical characterization is carried out by the scanning electron microscopy, X-ray diffraction, energy dispersive spectroscopy and UV–visible spectroscopy. The use of Ag as dopant did not alter the morphology of ZnO except sample 4 which has flower like morphology. The Ag, Zn and O are the main constituent of doped materials. The XRD revealed a hexagonal phase for ZnO and cubic phase for silver and confirmed the successful doping of Ag. The photocatalytic activity of Ag doped ZnO nanorods was investigated for the photo degradation of methyl orange. The photocatalytic measurements show that 88% degradation of methyl orange by the sample 4 within the 2 h of UV light treatment (365 nm) is significant advancement in the photocatalyst and provide the inexpensive and promising materials for the photochemical applications. © 2019 Elsevier Ltd and Techna Group S.r.l.
16.	Bu, Junfu, et al. (författare) Preparation of 30 mol.% Y-doped hafnia (Hf0.7Y0.3O2-delta) using a modified solid-state reaction method 2015 Ingår i: Ceramics International. - : Elsevier BV. - 0272-8842 .- 1873-3956. ; 41:2, s. 2611-2615 Tidskriftsartikel (refereegranskat)abstract A pure and well-crystallized Hf0.7Y0.3O2-delta (YSH) powder was synthesized using a modified solid-state reaction method. Water-based milling and freeze drying process were implemented to facilitate powder synthesis and final densification process. The improved powder performance, in aspects of phase development and sintering behaviour, was investigated by systematic comparison between different powder processing procedures. Dense YSH ceramic material with a relative density of 0.975 was successfully obtained using conventional sintering at 1650 degrees C for 10 h. XRD, SEM and EDS were employed to characterize the synthesized powder and dense YSH ceramics. Dense YSH ceramic possesses a fluorite cubic structure with an a value of 5.1406 angstrom, and the ionic radius of Y3+ in YSH was determined to be 0.1006 nm.
17.	Bu, Junfu, et al. (författare) Sintering behaviour of the protonic conductors BaZr(x)Ce(0.8-x)Ln(0.2)O(3-delta) (x=0.8, 0.5, 0.1; Ln=Y, Sm, Gd, Dy) during the solid-state reactive-sintering process 2015 Ingår i: Ceramics International. - : Elsevier BV. - 0272-8842 .- 1873-3956. ; 41:2, s. 2558-2564 Tidskriftsartikel (refereegranskat)abstract The protonic conductors BaZr(x)Ce(0.8-x)Ln(0.2)O(3-delta) (x=0.8, 0.5, 0.1; Ln=Y, Sm, Gd, Dy) were successfully prepared using a solid-state reactive-sintering method. NiO (1 wt.%) was added as a sintering aid, and it was proven that NiO produced tremendous enhancement in the densification process. The morphologies of the variously doped BaZr(0.8)Ln(0.2)O(3-delta), BaZr(0.5)Ce(0.3)Ln(0.2)O(3-delta) and BaZr(0.1)Ce(0.7)Ln(0.2)O(3-delta) ceramics, as well as their sintering behaviour, were investigated. The results show that the Ce content in the BaZr(0.8)Ln(0.2)O(3-delta), BaZr(0.5)Ce(0.3)Ln(0.2)O(3-delta) and BaZr(0.1)Ce(0.7)Ln(0.2)O(3-delta) compounds influences the sintering temperature significantly, and a larger Ce content will lead to a lower sintering temperature. In addition, ionic radii of the dopants that are similar to the ionic radii of the B-site will also result in a lowered sintering temperature. Based on the present study, NiO has no influence on the lattice parameters.
18.	Bu, Junfu, et al. (författare) Transport properties of BaZr0.5Ce0.3Y0.2O3-δ proton conductor prepared by spark plasma sintering 2016 Ingår i: Ceramics International. - : Elsevier. - 0272-8842 .- 1873-3956. ; 42:3, s. 4393-4399 Tidskriftsartikel (refereegranskat)abstract Dense BaZr0.5Ce0.3Y0.2O3-δ (BZCY532) proton conductors were prepared by a spark plasma sintering method. Their conductivities were determined in different atmospheres: dry air, wet N2 and wet H2. Moreover, the potential electronic conductivity contribution to the total conductivity was also identified by testing their total conductivities at different oxygen partial pressures (1-10-24 atm) in combination with an XPS analysis. It is found that the prepared dense BZCY532 ceramics are good proton conductors at 600 °C. In addition, the Ce3+ concentration in the dense BZCY532 ceramics is around 3.5 atm% of the total Ce element, and the electronic contribution to the total conductivity can be neglected after a postheat treatment.
19.	Chen, Qingguo, et al. (författare) Preparation and properties of Ce0.5Nd0.5PO4 monazite ceramics by pressureless sintering and spark plasma sintering (SPS) 2024 Ingår i: Ceramics International. - : Elsevier. - 0272-8842 .- 1873-3956. ; 50:12, s. 20803-20810 Tidskriftsartikel (refereegranskat)abstract LnPO4·nH2O rhabdophane/monazite is an important actinide-bearing material in the back end of the nuclear fuel cycle. In this work, using Nd3+ to simulate trivalent actinides, Ce0.5Nd0.5PO4·0.667H2O rhabdophane was synthesized by the wet-chemistry method in 90 °C and pH = 1 solution. The sintering behavior of associated Ce0.5Nd0.5PO4 monazite ceramics was investigated by pressureless sintering and spark plasma sintering (SPS), along with appraising their chemical stability. The results reveal that Ce3+ is successfully replaced by Nd3+ in the rhabdophane lattice, and rhabdophane can transform to monazite with a temperature over 750 °C. SPS can compact the ceramic sample at a lower temperature compared to pressureless sintering even if the grain size is smaller. Adding a pre-sintering process of 900 °C before SPS and pressureless sintering will further improve the density and Vickers hardness of ceramics. For the chemical stability of Ce0.5Nd0.5PO4 monazite ceramics, Ce is more likely to be leached compared to Nd, and the ceramics prepared by SPS with a pre-sintering process have the lowest normalized leaching rates, associated with the values of 2.03 × 10−5 g·m−2·d−1 and 0.75 × 10−5 g·m−2·d−1 for Ce and Nd, respectively.
20.	Chen, Song, et al. (författare) Eu3+ doped monetite and its use as fluorescent agent for dental restorations 2018 Ingår i: Ceramics International. - : Saunders Elsevier. - 0272-8842 .- 1873-3956. ; 44:9, s. 10510-10516 Tidskriftsartikel (refereegranskat)abstract It is essential but challenging to distinguish the dental restorations from the surrounding teeth when removing filling materials from cavity. In this study, Eu3+ doped monetite was proposed as a fluorescent agent for dental restorations to meet this challenge. Eu3+ doped monetite with enhanced fluorescent property was obtained via a precipitation method. The presence of Eu3+ could prevent the phase transformation of brushite to monetite. However, all the brushite particles transformed to monetite at 300 °C and to tricalcium phosphate at 800 °C. The emission intensity increased with the addition of Eu3+ and reached the maximum when 12 mol% Eu3+ was added into the aqueous solution. With either 254 nm or 393 nm excitation, Eu3+ doped monetite showed the strongest fluorescence emission peaking at 616 nm and other two moderate bands peaking at 699 nm and 593 nm. The excitation spectra at the emission wavelength of 616 nm showed strong absorption peaks at 254 nm and 393 nm. We further investigate the fluorescence properties of Eu3+ doped monetite in one type of dental restorations. Glass ionomer cement with Eu3+ doped monetite exhibited clear fluoresce with origin color under UV irradiation at 254 nm, showing that Eu3+doped monetite is a promising fluorescent agent for dental restorations.
21.	Cheng, Z., et al. (författare) Ink-jet printed BNT thin films with improved ferroelectric properties via annealing in wet air 2018 Ingår i: Ceramics International. - : Elsevier. - 0272-8842 .- 1873-3956. ; 44:9, s. 10700-10707 Tidskriftsartikel (refereegranskat)abstract In this work, an ink-jet printing process based on the sol-gel route was applied to prepare lead-free ferroelectric Na0.5Bi0.5TiO3(BNT) thin films for the first time. Dense and crack-free films with perovskite structure were obtained from a modified precursor solution through multiple printing and pyrolysis processes. The ferroelectric, dielectric and electrical properties were significantly affected by the annealing temperature and atmosphere. The film annealed at 670 °C in wet air showed a high remnant polarization of 24.7 μC/cm2 with a low coercive field of 263 kV/cm, the dielectric constant and loss were 185 and 0.1 at 10 kHz, respectively. It was found that wet air was an alternative to reduce oxygen vacancies and enhance properties of ferroelectric films, which can be explained by the defect chemical reaction between water and oxygen vacancies. X-ray photoelectron spectroscopy(XPS) confirmed the decrease of oxygen vacancies after annealing with water presence, with a formation of Ohmic conduction mechanism dominated by charged hydroxyl groups.
22.	Choopani, S., et al. (författare) Ferromagnetic resonance and magnetic anisotropy in biocompatible Y3Fe5O12@Na0.5K0.5NbO3 core-shell nanofibers 2019 Ingår i: Ceramics International. - : Elsevier Ltd. - 0272-8842 .- 1873-3956. ; 46:2, s. 2072-2078 Tidskriftsartikel (refereegranskat)abstract Y3Fe5O12@Na0.5K0.5NbO3 (YIG@NKN) core-shell nanofibers were synthesized by the coaxial electrospinning technique. For comparison, samples of YIG and NKN nanofibers were prepared. Scanning Electron Microscopy (SEM) and 3D laser-scanning confocal microscopy (TDLM) of YIG@NKN nanofibers revealed long uniform size distributed fibers with the average diameter of 100–150 nm. X-Ray diffraction (XRD) examination shows the existence of the distinct peaks of orthorhombic NKN and cubic YIG. Magnetic force microscopy (MFM) of individual YIG@NKN nanofiber demonstrates a magnetic core that is extended in one half of the diameter of the fiber. These nanofibers show obvious Ferromagnetic resonance (FMR) with resonance near 2 KOe similar to YIG fibers but in such a way that it starts to increase linearly with applying magnetic field from zero up to near resonance field. Also they show a soft magnetic behavior with saturation magnetization of 10 emu/gr. Furthermore, we propose a model to explain line shape of randomly oriented fibers and extract all the magnetic anisotropy parameters from FMR data. The results rely the shape anisotropy as dominant effect, however the dipolar field among fibers should be considered. The highest degree of asymmetry observed in the case of core-shell fibers in hard direction that it can be originated from magneto electric effects. By taking into account the observed FMR, the ability of adequate control of microwave absorption by applying magnetic field and biocompatibility, the synthesized core-shell nanofibers are the most promising candidate for clinical application such as microwave cancer thermotherapy and adjustable microwave absorbers.
23.	Dahl, P., et al. (författare) Densification and properties of zirconia prepared by three different sintering techniques 2007 Ingår i: Ceramics International. - : Elsevier BV. - 0272-8842 .- 1873-3956. ; 33:8, s. 1603-1610 Tidskriftsartikel (refereegranskat)abstract Densification of nanocrystalline yttria stabilized zirconia (YSZ) powder with 8 mol% Y2O3, prepared by a glycine/nitrate smoldering combustion method, was investigated by spark plasma sintering, hot pressing and conventional sintering. The spark plasma sintering technique was shown to be superior to the other methods giving dense materials (>= 96%) with uniform morphology at lower temperatures and shorter sintering time. The grain size of the materials was 0.21, 0.37 and 12 mu m after spark plasma sintering, hot pressing and conventional sintering, respectively. Total electrical conductivity of the materials showed no clear correlation with the grain size, but the activation energy for spark plasma sintered materials was slightly higher than for materials prepared by the two other densification methods. The hardness, measured by the Vickers indentation method, was found to be independent on grain size while fracture toughness, derived by the indentation method, was slightly decreasing with increasing grain size.
24.	Dey, J., et al. (författare) Non-collinear magnetic structure of the MAX phase Mn2GaC epitaxial films inferred from zero-field NMR study (CE-5:L05) 2023 Ingår i: Ceramics International. - : ELSEVIER SCI LTD. - 0272-8842 .- 1873-3956. ; 49:14, s. 24235-24238 Tidskriftsartikel (refereegranskat)abstract Zero-field NMR investigations on the 69Ga, 71Ga, and 55Mn nuclei have been performed at 4.2 K on a 100 nm thick epitaxial Mn2GaC(0001) MAX phase film grown on a MgO(111) substrate. This nano-laminated structure consists of ferromagnetic Mn-C-Mn stacks interleaved with monolayers of gallium. A resolved quadrupolar structure of the observed gallium resonances is a fingerprint of a well-defined crystal field confirming high crystal quality. The nuclei of non-magnetic gallium atoms are shown to experience the transferred hyperfine magnetic field of 15.75 T (& PLUSMN;0.05 T), which is due to polarization of their 4s electron shell by the magnetic moments of manganese neighbors, evidencing the presence of an uncompensated ferromagnetic moment within the manganese sublattice. The average magnetic moment of manganese was found to be around 2 & mu;B, strongly contrasting with the reported remnant magnetization of only 0.3 & mu;B. Moreover, the 55Mn NMR spectrum in-dicates the presence of magnetically non-equivalent manganese sites within this structure. The observed features of the 69,71Ga and 55Mn NMR spectra cannot be reconciled with any of the hitherto proposed collinear ar-rangements of manganese moments and suggest their non-collinear arrangement across a gallium layer. Nevertheless a more advanced study is required to elucidate the detailed nature of magnetic structure in this material.
25.	Dziewanowska, Julia, et al. (författare) Nanocrystallization as a tool for controlling in vitro dissolution of borophosphate glass 2023 Ingår i: Ceramics International. - : Elsevier. - 0272-8842 .- 1873-3956. ; 49:16, s. 27382-27390 Tidskriftsartikel (refereegranskat)abstract The controlled nanocrystallization of sodium-calcium-borophosphate glass (Na16.6Ca5.1B10.5Al0.8P10.5 O56.5 in at %) was conducted to investigate its influence on in vitro dissolution. Three temperatures (570 degrees C, 590 degrees C, and 610 degrees C) were selected based on thermal analysis and investigation of the morphology, structure, and in vitro dissolution of glass and glass-ceramics was conducted. The results of X-ray diffraction confirmed the presence of calcium phosphates nanocrystallites in glass-ceramics, with their contents increasing proportionally to the crystallization temperature. Infrared spectroscopy showed the presence of phosphate and borate network units, along with phosphates in a crystalline form. It was found that the target glass shows the highest mass loss in comparison to the glass-ceramics. Controlled nanocrystallization slowed down the dissolution of the materials (>10%), but did not adversely affect the deposition of hydroxyapatite layer. The presence of calcium phosphate nanocrystallites favors the process of B3+ release. The nanocrystallization of borophosphate glasses is a perspective tool for controlling the rate of dissolution of bioactive materials and enhancing their ability to de-posit hydroxyapatite on their surface.

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