SwePub - search: WFRF:(Vomiero Alberto)

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1.	Bortoluzzi, Marco, et al. (author) Luminescent lanthanide complexes with phosphoramide and arylphosphonic diamide ligands 2020 In: Chemické zvesti. - : Springer. - 0366-6352 .- 1336-9075. ; 74:11, s. 3693-3704 Journal article (peer-reviewed)abstract The sensitization of Eu(III) luminescence by the phosphoramide and arylphosphonic diamide ligands OP(NMe2)2Ind, OP(NMe2)2Cbz, OP(NMe2)2Ph, OP(NMe2)2(1-Naph) and OP(NMe2)2(2-Naph) (Ind = indol-1-yl; Ph = phenyl; Cbz = carbazol-9-yl; 1-Naph = naphtalen-1-yl; 2-Naph = naphtalen-2-yl) was verified by coordination to the [Eu(NO3)3] metal fragment. The emission spectra of the corresponding complexes showed only the 5D0 → 7FJ transitions of the metal centre, with the exception of the carbazolyl derivative. Some of the ligands were also able to sensitize Tb(III) luminescence, in agreement with the triplet state energies estimated from the phosphorescence spectra of the analogous Gd(III) nitrates. On the basis of the photoluminescence results achieved using nitrate as ancillary ligand, heptacoordinate Eu(III) complexes having general formula [Eu(β-dike)3L] (β-dike = dibenzoylmethanate, tenoyltrifluoroacetonate; L = phosphoramide or arylphosphomic diamide ligand) were prepared and characterized. All the complexes exhibited bright red emission upon excitation with near-UV and violet-blue light, with intrinsic quantum yields ranging between 18 and 36%.
2.	Afanasiev, Sergey V., et al. (author) Experimental apparatus to study crystal channeling in an external SPS beamline 2007 In: Proceedings of SPIE, the International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 6634 Journal article (peer-reviewed)abstract For the new generation of high intensity hadronic machines as, for instance, LHC, halo collimation is a necessary issue for the accelerator to operate at the highest possible luminosity and to prevent the damage of superconductor magnets.1 We propose an experiment aimed to systematic study of the channeling phenomenology and of the newly observed "volume reflection" effect. This experiment will be performed for an external SPS beamline and will make use of a primary proton beam with 400 GeV/c momentum and very small (∼ 3 μrad) divergence. The advantage of a proposed experiment is precise tracking of particles that interacted with a crystal, so that to determine the single-pass efficiency for all the processes involved. For this purpose, a telescope equipped with high-resolution silicon microstrip detectors will be used. New generation silicon crystals and an extra-precise goniometer are mandatory issues. Main goal of the experiment is to get the precise information on channeling of relativistic particles and, ultimately, on the feasibility of such technique for halo collimation at LHC. In this contribution we review the status of the setting-up of experimental apparatus and its future development in sight of the planned run in September 2006.
3.	Boscarino, Diego, et al. (author) Deposition of silica-silver nanocomposites by magnetron cosputtering 2005 In: Journal of Vacuum Science & Technology B. - : American Vacuum Society. - 1071-1023 .- 1520-8567. ; 23:1, s. 11-19 Journal article (peer-reviewed)abstract Thin films have been grown on silicon and silica substrates by cosputtering of silica and silver in Ar, Ar+2.5% O2, and Ar+5% O2 gas mixtures. Rutherford backscattering spectrometry showed that the films have Ag atomic fractions xAg in the range of ∼1 to ∼10 at. %, and, by valence considerations, that the fraction of oxidized Ag in the films deposited in presence of oxygen is limited. Transmission electron microscopy images revealed the presence of Ag nanoclusters, with a mean size diameter not larger than 5 nm. The clusters are preferentially arranged along columns. It is suggested that the columns are regions with diameter in the nanometer range in which the density of the dielectric matrix is lower, thus favoring the formation of metal clusters. In presence of O2, the clusters were observed to have a more regular spherical shape. The optical absorption spectra of films grown in presence of O2 are distinguished from those grown in Ar by specific features, which are attributed to oxidation at the cluster surface. © 2005 American Vacuum Society.
4.	Maggioni, Gianluigi, et al. (author) Effects of heat treatments on the properties of copper phthalocyanine films deposited by glow-discharge-induced sublimation 2006 In: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 18:17, s. 4195-4204 Journal article (peer-reviewed)abstract Copper phthalocyanine films have been deposited by glow-discharge-induced sublimation. The films have undergone postdeposition heat treatments in air at 250 and 290°C for different times, ranging from 30 min to 14 h. The properties of as-deposited and heated films have been investigated by different techniques in order to determine the effects of heat treatments on the film properties. Fourier transform infrared analysis and UV-visible optical absorption analysis point out a gradual evolution of the film structure from a mixture of α and β polymorphs to the only β polymorph in the sample heated at 290°C for 14 h. A pronounced decrease of carbon and nitrogen atomic percentages against an oxygen increase in the heated films are shown by ion beam analyses (Rutherford backscattering spectrometry and nuclear reaction analysis) and X-ray photoelectron spectroscopy (XPS). X-ray absorption spectroscopy and XPS indicate that part of the copper phthalocyanine molecules decompose during heat treatments and the formation of copper oxide takes place. The replacement of copper phthalocyanine by copper oxide in the heated films accounts for the change of their surface electrical conductance and of their electrical response to NO 2. © 2006 American Chemical Society.
5.	Maggioni, Gianluigi, et al. (author) Production and characterization of thin film materials for indoor optical gas sensing applications 2006 In: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 41:1, s. 531-534 Journal article (peer-reviewed)abstract Pure and Nile-Red-doped polyimide and porphyrin films have been deposited and their optical response to different organic vapours has been tested. Polyimide films were obtained by spin coating a solution containing 4, 4'-4, 4'-(hexafluoroisopropylidene) diphthalic anhydride and 2, 3, 5, 6-tetramethyl-1, 4-phenylenediamine. Free, cobalt and iron chloride 5, 10, 15, 20 meso-tetraphenyl porphyrin films were deposited by spin coating and by high vacuum evaporation. Exposure to water, ethanol and isopropanol vapours produce reversible changes of the fluorescence features of both pure and doped polyimide films. Exposure to methanol, ethanol and isopropanol vapours gives rise to changes of the optical absorption of porphyrin films. The results of the optical measurements point out that the synthesized films can be used for the detection of volatile organic compounds. © 2006 IOP Publishing Ltd.
6.	Scandale, Walter, et al. (author) Apparatus to study crystal channeling and volume reflection phenomena at the SPS H8 beamline 2008 In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 79:2 Journal article (peer-reviewed)abstract A high performance apparatus has been designed and built by the H8-RD22 collaboration for the study of channeling and volume reflection phenomena in the interaction of 400 GeVc protons with bent silicon crystals, during the 2006 data taking in the external beamline H8 of the CERN SPS. High-quality silicon short crystals were bent by either anticlastic or quasimosaic effects. Alignment with the highly parallel (8 μrad divergence) proton beam was guaranteed through a submicroradian goniometric system equipped with both rotational and translational stages. Particle tracking was possible by a series of silicon microstrip detectors with high-resolution and a parallel plate gas chamber, triggered by various scintillating detectors located along the beamline. Experimental observation of volume reflection with 400 GeVc protons proved true with a deflection angle of (10.4±0.5) μrad with respect to the unperturbed beam, with a silicon crystal whose (111) planes were parallel to the beam. © 2008 American Institute of Physics.
7.	Scandale, Walter, et al. (author) Deflection of 400GeV/c proton beam with bent silicon crystals at the CERN Super Proton Synchrotron 2008 In: Physical Review Special Topics - Accelerators and Beams. - 1098-4402. ; 11:6 Journal article (peer-reviewed)abstract This paper presents a detailed study of the deflection phenomena of a 400GeV/c proton beam impinging on a new generation of bent silicon crystals; the tests have been performed at the CERN Super Proton Synchrotron H8 beam line. Channeling and volume reflection angles are measured with an extremely precise goniometer and with high resolution silicon microstrip detectors. Volume reflection has been observed and measured for the first time at this energy, with a single-pass efficiency as large as 98%, in good agreement with the simulation results. This efficiency makes volume reflection a possible candidate for collimation with bent crystals at the CERN Large Hadron Collider. © 2008 The American Physical Society.
8.	Scandale, Walter, et al. (author) Double volume reflection of a proton beam by a sequence of two bent crystals 2008 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 658:4, s. 109-111 Journal article (peer-reviewed)abstract The doubling of the angle of beam deflection due to volume reflection of protons by a sequence of two bent silicon crystals was experimentally observed at the 400 GeV proton beam of the CERN SPS. A similar sequence of short bent crystals can be used as an efficient primary collimator for the Large Hadron Collider.
9.	Scandale, Walter, et al. (author) High-efficiency volume reflection of an ultrarelativistic proton beam with a bent silicon crystal 2007 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 98:15 Journal article (peer-reviewed)
10.	Scrivanti, Alberto, et al. (author) Luminescent europium(III) complexes containing an electron rich 1,2,3-triazolyl-pyridyl ligand 2018 In: New Journal of Chemistry. - : Royal Society of Chemistry. - 1144-0546 .- 1369-9261. ; 42:13, s. 11064-11072 Journal article (peer-reviewed)abstract An improved synthesis of the electron-rich N,N-chelating ligand, 2-(1-t-butyl-1H-1,2,3-triazol-4-yl)pyridine (L), has been developed by coupling t-butyl-azide with ethynylpyridine in the presence of a Cu(I) catalyst. L has been employed in the preparation of lanthanide coordination compounds having formulae [Ln(κ2-NO3)3L2] and [Eu(dbm)3L] (Ln = Eu, Tb; dbm = dibenzoylmethanate). The molecular structure of [Eu(dbm)3L] has been determined by X-ray diffraction studies. All the new complexes exhibit good photoluminescence properties and [Eu(dbm)3L] has been successfully used as the dopant for the preparation of luminescent plastic materials.
11.	Vomiero, Alberto, et al. (author) Effects of thermal annealing on the structural properties of sputtered W-Si-N diffusion barriers 2004 In: Materials Science in Semiconductor Processing. - : Elsevier BV. - 1369-8001 .- 1873-4081. ; 7:4-6 SPEC. ISS., s. 325-330 Journal article (peer-reviewed)abstract W-Si-N thin films were deposited via rf-magnetron sputtering from a W 5Si3 target in Ar/N2 reactive gas mixtures over a large range of compositions, obtained by varying the partial flow of nitrogen within the reaction chamber. The samples of each set were then thermally annealed in vacuum at different temperatures up to 980°C. Film composition was determined by Rutherford backscattering spectrometry (RBS), surface film morphology by scanning electron microscopy (SEM), micro-structure by transmission electron microscopy (TEM), vibrational properties by FT-IR absorption and Raman scattering spectroscopy, and electrical resistivity by four-point probe measurements. Independently of the deposition conditions, all the as-deposited films have an amorphous structure, while their composition varies, showing an increase of Si/W ratio from 0.1 up to 0.55 when the nitrogen concentration in the films increases from 0 to 60 at%. Thermal treatments in vacuum induce an important loss of nitrogen in the nitrogen-rich samples, especially at temperatures higher than 600°C. Samples with high nitrogen content preserve their amorphous structure even at the highest annealing temperature, despite the chemical bonding ordering observed by means of FTIR measurements. Raman spectroscopy of as-deposited films rich in nitrogen suggests the presence of an important amorphous silicon nitride component, but fails to detect any structural rearrangement either within the composite matrix of film or within silicon nitride component. Segregation of metallic tungsten was detected by TEM in the annealed sample with lowest nitrogen content (W 58Si21N21). Finally, the resistivity of the films increases with the N content, while the loss of nitrogen accompanies the decrease of resistivity especially of samples with high nitrogen content. © 2004 Elsevier Ltd. All rights reserved.
12.	Vomiero, Alberto, et al. (author) Structural and functional characterization of W-Si-N sputtered thin films for copper metallizations 2004 In: Materials Research Society Symposium Proceedings. - 0272-9172 .- 1946-4274. ; 812, s. 153-158 Journal article (peer-reviewed)abstract Ternary W-Si-N thin films have been reactively sputter-deposited from a W5Si3 target at different nitrogen partial pressures. The composition has been determined by 2.2 MeV 4He+ beam, the structure by x-ray diffraction and transmission electron microscope, the chemical bonds by Fourier transform - infrared spectroscopy and the surface morphology by scanning electron microscopy. Electrical resistivity was measured by four point probe technique on the as grown films. The film as-deposited is amorphous with the Si/W ratio increasing from about 0.1 up to 0.55 with the nitrogen content going from 0 to 60 at%. The heat treatments up to 980°C induce a loss of nitrogen in the nitrogen rich samples. Segregation of metallic tungsten occurs in the sample with low nitrogen content (W58Si 21N21). Samples with high nitrogen content preserve the amorphous structure, despite of the precipitation of a more ordered phase inferred by FT-IR absorbance spectrum of the layer treated at highest temperature. The surface morphology depends upon the nitrogen content; the loss of nitrogen induces the formation of blistering and in the most nitrogen rich sample the formation of holes. Electrical resistivity preliminary results on the as grown layers range between 500 and 4750 μΩcm passing from the lowest to the highest N concentration.
13.	Vomiero, Alberto, et al. (author) Structure and morphology of surface of silicon crystals to be applied for channeling at relativistic energies 2006 In: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 249:1-2 SPEC. ISS., s. 903-906 Journal article (peer-reviewed)abstract Bent crystals can be successfully applied for extraction/collimation of relativistic particles. A crucial feature to obtain high extraction efficiencies is the treatment of the surfaces being encountered by the beam, since mechanical operations induce considerable lattice imperfections. In order to remove the superficial damaged layer a planar etching can be applied on the surface exposed to the beam. This work presents a systematic study of the morphology and the crystalline perfection of the surface of the samples that have been used in accelerators with high efficiency. Crystals with different surface treatments have been investigated. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were applied on the characterisation of surface morphology. Low energy backscattering channeling of 2-MeV α particles or protons was used as a probe for the crystalline structure. The presence of a superficial damaged layer in the samples just after mechanical treatment was unveiled, while, in contrast, chemical etching leaves a surface with high crystalline perfection that can be related to the record efficiency. © 2006 Elsevier B.V. All rights reserved.
14.	Adeel, Muhammad, et al. (author) 2D metal azolate framework as nanozyme for amperometric detection of glucose at physiological pH and alkaline medium 2021 In: Microchimica Acta. - : Springer. - 0026-3672 .- 1436-5073. ; 188:3 Journal article (peer-reviewed)abstract The synthesis of Co-based two-dimensional (2D) metal azolate framework nanosheets (MAF-5-CoII NS) is described using a simple hydrothermal method. The product was isostructural to MAF-5 (Zn). The as-prepared MAF-5-CoII NS exhibited high surface area (1155 m2/g), purity, and crystallinity. The MAF-5-CoII NS–modified screen-printed electrode (MAF-5-CoII NS/SPE) was used for nonenzymatic detection of glucose in diluted human blood plasma (BP) samples with phosphate buffer saline (PBS, pH 7.4) and NaOH (0.1 M, pH 13.0) solutions. The MAF-5-CoII NS nanozyme displayed good redox activity in both neutral and alkaline media with the formation of CoII/CoIII redox pair, which induced the catalytic oxidation of glucose. Under the optimized detection potential, the sensor presented a chronoamperometric current response for the oxidation of glucose with two wide concentration ranges in PBS-diluted (62.80 to 180 μM and 305 to 8055 μM) and NaOH-diluted (58.90 to 117.6 μM and 180 to 10,055 μM) BP samples, which were within the limit of blood glucose levels of diabetic patients before (4.4–7.2 mM) and after (10 mM) meals (recommended by the American Diabetes Association). The sensor has a limit of detection of ca. 0.25 and 0.05 μM, respectively, and maximum sensitivity of ca. 36.55 and 1361.65 mA/cm2/mM, respectively, in PBS- and NaOH-diluted BP samples. The sensor also displayed excellent stability in the neutral and alkaline media due to the existence of hydrophobic linkers (2-ethyl imidazole) in the MAF-5-CoII NS, good repeatability and reproducibility, and interference-free signals. Thus, MAF-5-CoII NS is a promising nanozyme for the development of the disposable type of sensor for glucose detection in human body fluids.
15.	Aftab, Umair, et al. (author) Two step synthesis of TiO2–Co3O4 composite for efficient oxygen evolution reaction 2021 In: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 46:13, s. 9110-9122 Journal article (peer-reviewed)abstract For an active hydrogen gas generation through water dissociation, the sluggish oxygen evolution reaction (OER) kinetics due to large overpotential is a main hindrance. Herein, a simple approach is used to produce composite material based on TiO2/Co3O4 for efficient OER and overpotential is linearly reduced with increasing amount of TiO2. The scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) investigations reveal the wire like morphology of composite materials, formed by the self-assembly of nanoparticles. The titania nanoparticles were homogenously distributed on the larger Co3O4 nanoparticles. The powder x-ray diffraction revealed a tetragonal phase of TiO2 and the cubic phase of Co3O4 in the composite materials. Composite samples with increasing TiO2 content were obtained (18%, 33%, 41% and 65% wt.). Among the composites, cobalt oxide-titanium oxide with the highest TiO2 content (CT-20) possesses the lowest overpotential for OER with a Tafel slope of 60 mV dec−1 and an exchange current density of 2.98 × 10−3A/cm2. The CT-20 is highly durable for 45 h at different current densities of 10, 20 and 30 mA/cm2. Electrochemical impedance spectroscopy (EIS) confirmed the fast charge transport for the CT-20 sample, which potentially accelerated the OER kinetics. These results based on a two-step methodology for the synthesis of TiO2/Co3O4 material can be useful and interesting for various energy storage and energy conversion systems.
16.	Ahdikari, Rajesh, et al. (author) High Efficiency, Pt-free Photoelectrochemical Cells for Solar Hydrogen Generation based on “Giant” Quantum Dots 2016 In: Nano Energy. - : Elsevier BV. - 2211-2855. ; 27, s. 265-274 Journal article (peer-reviewed)abstract Quantum dot (QD) sensitized TiO2 is considered as a highly promising photoanode material for photoelectrochemical (PEC) solar hydrogen production. However, due to its limited stability, the photoanode suffers from degradation of its long-term PEC performance. Here, we report the design and characterization of a high-efficiency and long-term stable Pt-free PEC cell. The photoanode is composed of a mesoporous TiO2 nanoparticle film sensitized with “giant” core@shell QDs for PEC solar hydrogen generation. The thick shell enhances light absorption in the visible range, increases the stability of the QDs and does not inhibit charge separation, injection and transport, needed for proper operation of the device. We prepared thin films of Cu2S nanoflakes through a simple and reproducible procedure, and used them as counter-electrodes replacing the standard Pt film, resulting in equivalent performances of the PEC cell. We obtained an unprecedented photocurrent density (~10 mA/cm2) for “giant” QDs based PEC devices (and corresponding H2 generation) and a very promising stability, indicating that the proposed cell architecture is a good candidate for long-term stable QD-based PEC solar hydrogen generation.
17.	Akbar, Kamran, et al. (author) Carbon Dots for Photocatalytic Degradation of Aqueous Pollutants : Recent Advancements 2021 In: Advanced Optical Materials. - : John Wiley & Sons. - 2162-7568 .- 2195-1071. ; 9:17 Research review (peer-reviewed)abstract The immense progress of humanity on the technological, domestic, and industrial fronts comes at the cost of polluting the planet. Aquatic pollution is particularly dangerous since all life forms are directly linked to it. Each year tons of industrial and domestic pollutants make their way into aqueous systems. Efficient removal/degradation of these pollutants is of prime importance for the sustainable future. Among many technologies, photodegradation is an emerging and promising method for the successful removal of aqueous pollutants since it is powered by abundant solar light. The last decade had shown that carbon dots are among the most promising materials that can be utilized as an efficient tool to derive various solar-driven chemical reactions. Carbon dots possess unique photophysical and chemical properties such as light-harvesting over a broad-spectrum region, upconversion photoluminescence, photosensitizers, chemical inertness, and bivalent redox character, etc. The ease of synthesis of carbon dots at low cost also contributes hugely to their utilizations as an efficient photocatalyst for the degradation of aqueous pollutants. This review summarizes the recent progress made in the field of photodegradation of aqueous pollutants with the aid of carbon dots and their hybrids, highlighting the critical role carbon dots can play in the field.
18.	Alberoni, Chiara, et al. (author) Ceria doping boosts methylene blue photodegradation in titania nanostructures 2021 In: Materials Chemistry Frontiers. - : Royal Society of Chemistry. - 2052-1537. ; 5:11, s. 4138-4152 Journal article (peer-reviewed)abstract Ceria-doped titania photocatalysts (ceria loading 0.25–5.0 wt%) were synthesized by hydrothermal methods for water remediation. Nanotubes (CeTNTx) and nanoparticles (CeTNPx) were obtained. Ceria doping was applied to tune the electronic properties of nanostructured titania, boosting its photocatalytic activity. CeTNT nanostructures contained anatase as the only titania phase, whereas the CeTNP series consisted of both anatase and rutile polymorphs. The Ce addition induced a decrease in the energy gap, allowing enhancement of visible light harvesting. The photodegradation of methylene blue, MB, in aqueous solution was chosen to study the influence of the morphology and the ceria loading on the photocatalytic response, under UV and solar light. Both CeO2–TiO2 nanoparticles and nanotubes were found to be very active under UV light. The highest MB degradation rates were obtained for the 0.25 wt% CeO2 doping, for both nanotubes and nanoparticles (0.123 and 0.146 min−1, respectively), able to photodegrade completely the dye after 120 min. The two samples are stable after a 3-cycle reusability test. The photo-response under simulated solar light confirmed that doping titania with ceria allows harvesting visible light absorption, enhancing its photoactivity. A maximum efficiency of 85% under simulated sunlight at a degradation rate of 0.054 min−1 was obtained. Transient photoluminescence confirmed that MB acts as a charge scavenger for the composite system. These results pointed out ceria-doped titania nanostructures as a promising class of photocatalysts for the degradation of dyes and other hazardous organic compounds in wastewater.
19.	Alvi, Sajid Ali, et al. (author) Adaptive nanolaminate coating by atomic layer deposition 2019 In: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 692 Journal article (peer-reviewed)abstract Atomic layer deposition (ALD) was used to deposit ZnO/Al2O3/V2O5 nanolaminate coatings to demonstrate a coating system with temperature adaptive frictional behaviour. The nanolaminate coating exhibited excellent conformity and crack-free coating of thickness 110 nm over Inconel 718 substrate. The ALD trilayer coating showed a hardness and elastic modulus of 12 GPa and 193 GPa, respectively. High-temperature tribology of the nanolaminate trilayer was tested against steel ball in dry sliding condition at 25 °C (room temperature, RT), 200 °C, 300 °C, and 400 °C. It was found that the nanolaminate coating showed a low coefficient of friction (COF) and wear rate at RT and 300 °C. The trilayer coating was found intact and stable at all temperatures during the friction tests. The adaptability of nanolaminate coating with the temperature was verified by performing the cyclic friction test at 300 °C and RT. The low COF and wear rate had been attributed to the (100) and (002) basal plane sliding of ZnO top layer, and the interlayer sliding of weakly bonded planes parallel to (001) plane in V2O5 bottom layer. Furthermore, even after the removal of ZnO coating during the tribotest, the bottom V2O5 layer coating stabilized the COF and wear rate at RT and 300 °C.
20.	Alvi, Sajid, et al. (author) Enhanced mechanical, thermal and electrical properties of high‐entropy HfMoNbTaTiVWZr thin film metallic glass and its nitrides 2022 In: Advanced Engineering Materials. - : John Wiley & Sons. - 1438-1656 .- 1527-2648. ; 24:9 Journal article (peer-reviewed)abstract The inception of high-entropy alloy promises to push the boundaries for new alloy design with unprecedented properties. This work reports entropy stabilisation of an octonary refractory, HfMoNbTaTiVWZr, high-entropy thin film metallic glass, and derived nitride films. The thin film metallic glass exhibited exceptional ductility of ≈60% strain without fracture and compression strength of 3 GPa in micro-compression, due to the presence of high density and strength of bonds. The thin film metallic glass shows thermal stability up to 750 °C and resistance to Ar-ion irradiation. Nitriding during film deposition of HfMoNbTaTiVWZr thin film of strong nitride forming refractory elements results in deposition of nanocrystalline nitride films with compressive strength, hardness, and thermal stability of up to 10 GPa, 18.7 GPa, and 950 °C, respectively. The high amount of lattice distortion in the nitride films leads to its insulating behaviour with electrical conductivity as low as 200 S cm−1 in the as-deposited film. The design and exceptional properties of the thin film metallic glass and derived nitride films may open up new avenues of development of bulk metallic glasses and the application of refractory-based high entropy thin films in structural and functional applications.
21.	Alvi, Sajid, et al. (author) Synthesis and Mechanical Characterization of a CuMoTaWV High-Entropy Film by Magnetron Sputtering 2020 In: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 12:18, s. 21070-21079 Journal article (peer-reviewed)abstract Development of high-entropy alloy (HEA) films is a promising and cost-effective way to incorporate these materials of superior properties in harsh environments. In this work, a refractory high-entropy alloy (RHEA) film of equimolar CuMoTaWV was deposited on silicon and 304 stainless-steel substrates using DC-magnetron sputtering. A sputtering target was developed by partial sintering of an equimolar powder mixture of Cu, Mo, Ta, W, and V using spark plasma sintering. The target was used to sputter a nanocrystalline RHEA film with a thickness of ∼900 nm and an average grain size of 18 nm. X-ray diffraction of the film revealed a body-centered cubic solid solution with preferred orientation in the (110) directional plane. The nanocrystalline nature of the RHEA film resulted in a hardness of 19 ± 2.3 GPa and an elastic modulus of 259 ± 19.2 GPa. A high compressive strength of 10 ± 0.8 GPa was obtained in nanopillar compression due to solid solution hardening and grain boundary strengthening. The adhesion between the RHEA film and 304 stainless-steel substrates was increased on annealing. For the wear test against the E52100 alloy steel (Grade 25, 700–880 HV) at 1 N load, the RHEA film showed an average coefficient of friction (COF) and wear rate of 0.25 (RT) and 1.5 (300 °C), and 6.4 × 10–6 mm3/N m (RT) and 2.5 × 10–5 mm3/N m (300 °C), respectively. The COF was found to be 2 times lower at RT and wear rate 102 times lower at RT and 300 °C than those of 304 stainless steel. This study may lead to the processing of high-entropy alloy films for large-scale industrial applications.
22.	Amin, Sidra, et al. (author) A practical non-enzymatic urea sensor based on NiCo 2 O 4 nanoneedles 2019 In: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 9:25, s. 14443-14451 Journal article (peer-reviewed)abstract We propose a new facile electrochemical sensing platform for determination of urea, based on a glassy carbon electrode (GCE) modified with nickel cobalt oxide (NiCo 2 O 4 ) nanoneedles. These nanoneedles are used for the first time for highly sensitive determination of urea with the lowest detection limit (1 μM) ever reported for the non-enzymatic approach. The nanoneedles were grown through a simple and low-temperature aqueous chemical method. We characterized the structural and morphological properties of the NiCo 2 O 4 nanoneedles by TEM, SEM, XPS and XRD. The bimetallic nickel cobalt oxide exhibits nanoneedle morphology, which results from the self-assembly of nanoparticles. The NiCo 2 O 4 nanoneedles are exclusively composed of Ni, Co, and O and exhibit a cubic crystalline phase. Cyclic voltammetry was used to study the enhanced electrochemical properties of a NiCo 2 O 4 nanoneedle-modified GCE by overcoming the typical poor conductivity of bare NiO and Co 3 O 4 . The GCE-modified electrode is highly sensitive towards urea, with a linear response (R 2 = 0.99) over the concentration range 0.01-5 mM and with a detection limit of 1.0 μM. The proposed non-enzymatic urea sensor is highly selective even in the presence of common interferents such as glucose, uric acid, and ascorbic acid. This new urea sensor has good viability for urea analysis in urine samples and can represent a significant advancement in the field, owing to the simple and cost-effective fabrication of electrodes, which can be used as a promising analytical tool for urea estimation.
23.	Amin, Sidra, et al. (author) A practical non-enzymatic urea sensor based on NiCo2O4 nanoneedles 2019 In: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 9:25, s. 14443-14451 Journal article (peer-reviewed)abstract We propose a new facile electrochemical sensing platform for determination of urea, based on a glassy carbon electrode (GCE) modified with nickel cobalt oxide (NiCo2O4) nanoneedles. These nanoneedles are used for the first time for highly sensitive determination of urea with the lowest detection limit (1 mu M) ever reported for the non-enzymatic approach. The nanoneedles were grown through a simple and low-temperature aqueous chemical method. We characterized the structural and morphological properties of the NiCo2O4 nanoneedles by TEM, SEM, XPS and XRD. The bimetallic nickel cobalt oxide exhibits nanoneedle morphology, which results from the self-assembly of nanoparticles. The NiCo2O4 nanoneedles are exclusively composed of Ni, Co, and O and exhibit a cubic crystalline phase. Cyclic voltammetry was used to study the enhanced electrochemical properties of a NiCo2O4 nanoneedle-modified GCE by overcoming the typical poor conductivity of bare NiO and Co3O4. The GCE-modified electrode is highly sensitive towards urea, with a linear response (R-2 = 0.99) over the concentration range 0.01-5 mM and with a detection limit of 1.0 mu M. The proposed non-enzymatic urea sensor is highly selective even in the presence of common interferents such as glucose, uric acid, and ascorbic acid. This new urea sensor has good viability for urea analysis in urine samples and can represent a significant advancement in the field, owing to the simple and cost-effective fabrication of electrodes, which can be used as a promising analytical tool for urea estimation.
24.	Amin, Sidra, et al. (author) A practical non-enzymatic urea sensor based on NiCo2O4 nanoneedles 2019 In: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 9:25, s. 14443-14451 Journal article (peer-reviewed)abstract We propose a new facile electrochemical sensing platform for determination of urea, based on a glassy carbon electrode (GCE) modified with nickel cobalt oxide (NiCo2O4) nanoneedles. These nanoneedles are used for the first time for highly sensitive determination of urea with the lowest detection limit (1 μM) ever reported for the non-enzymatic approach. The nanoneedles were grown through a simple and low-temperature aqueous chemical method. We characterized the structural and morphological properties of the NiCo2O4 nanoneedles by TEM, SEM, XPS and XRD. The bimetallic nickel cobalt oxide exhibits nanoneedle morphology, which results from the self-assembly of nanoparticles. The NiCo2O4 nanoneedles are exclusively composed of Ni, Co, and O and exhibit a cubic crystalline phase. Cyclic voltammetry was used to study the enhanced electrochemical properties of a NiCo2O4 nanoneedle-modified GCE by overcoming the typical poor conductivity of bare NiO and Co3O4. The GCE-modified electrode is highly sensitive towards urea, with a linear response (R2 = 0.99) over the concentration range 0.01–5 mM and with a detection limit of 1.0 μM. The proposed non-enzymatic urea sensor is highly selective even in the presence of common interferents such as glucose, uric acid, and ascorbic acid. This new urea sensor has good viability for urea analysis in urine samples and can represent a significant advancement in the field, owing to the simple and cost-effective fabrication of electrodes, which can be used as a promising analytical tool for urea estimation.
25.	Amin, Sidra, et al. (author) A sensitive enzyme-free lactic acid sensor based on NiO nanoparticles for practical applications 2019 In: Analytical Methods. - : Royal Society of Chemistry. - 1759-9660 .- 1759-9679. ; 11, s. 3578-3583 Journal article (peer-reviewed)abstract A facile and efficient electrochemical sensing platform has been successfully exploited for the first time for the determination of lactic acid using a nickel oxide (NiO) nanoparticle-modified glassy carbon electrode (GCE). Nickel oxide nanoparticles were prepared by a chemical growth method using different quantities of arginine as a soft template. The structural and morphological properties of NiO nanoparticles were characterized by Raman spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Cyclic voltammetry (CV) was used to study the electrochemical properties of various samples. The modified electrode is highly sensitive and presents a linear response over a wide range (0.005–5 mM) of lactic acid concentrations in 0.1 M NaOH. The detection limit for the sensor was found to be 5.7 μM, and it exhibits good stability. Furthermore, the sensor shows excellent selectivity in the presence of common interfering species. The lactic acid sensor showed good viability for lactic acid analysis in real samples (milk, yogurt and red wine) and demonstrated significant advancement in sensor technology for practical applications.

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