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[en] This is with reference to Mater. Sci. Eng. B 234 (2017) 28–39, the journal publication entitled “Positron annihilation spectroscopy and photoluminescence investigation of LaOF:Tb3+ nanophosphor fabricated via ultrasound assisted sonochemical route”. The doi link of the publication is https://doi.org/10.1016/j.mseb.2017.07.001 which was published on October 2017. It is to be informed to all the readers and the journal officials that there has been inadvertent mistake in the authors list of this publication by leaving two important authors name who contributed significantly for the PALS and CDBS discussions. Hence in the authors list two important author names and their affiliations were included. Further, there is a change in one of the sentence of acknowledgement as noted below: K. Hareesh received an Australian Endeavour and India Council Postdoctoral Research Fellowship. The Australian Research Council and the University of Western Australia partially supported the research.” is to be included instead of “Authors thanks to Prof. J.F. Williams and Dr. K. Hareesh of University of Western Australia, Perth WA-6009, Australia for recording PALS and CDBS data. The authors would like to apologise for any inconvenience caused.
[en] Highlights: • Substitution of B by Ge can reduce the primary crystallization temperature Tx1. • The ΔTx enlarges about 180 °C with Ge increasing. • The μi of 600 °C-annealed Ge = 3 alloy above 1000 at 10 kHz can be kept up to 550 °C. - Abstract: The nanocrystalline (Fe0.9Co0.1)73.5Si13.5B9−xNb3Cu1Gex alloys were obtained by partial devitrification of their amorphous precursors. The influence of partial substitution of B by Ge on the microstrucural evolution of these alloys was studied by means of X-ray diffraction (XRD) and differential scanning calorimeter (DSC). The temperature dependence of initial permeability (μi-T curves) for (Fe0.9Co0.1)73.5Si13.5B6Nb3Cu1Ge3 alloys heating–cooling cycled at 450–650 °C was mainly measured. It was found that the Ge doping into (Fe0.9Co0.1)73.5Si13.5B9Nb3Cu1 alloy can reduce the onset primary crystallization temperature (Tx1), enlarge the interval temperature (ΔTx) from 129 °C to 180 °C and improve the high temperature soft magnetic properties, especially for (Fe0.9Co0.1)73.5Si13.5B6Nb3Cu1Ge3 alloy. After annealed at 450–650 °C for the alloy with x = 3, the optimum high temperature magnetic softness was observed in 600 °C-annealed sample, the μi above 1000 at 10 kHz can be kept up to 550 °C, which is due to the higher crystallization phase volume fraction and the thinner amorphous layer thickness and an enhancement of the exchange stiffness in the intergranular region.
[en] Highlights: • Ga–Sn–Zn–O (GTZO) thin films were deposited on glass substrates via the radio-frequency (RF) magnetron sputtering method at room temperature. • The resistivity of GTZO films decreased from 78 to 19.5 Ω cm when the oxygen content was decreased from 10.7 to 0%. • GTZO films have an average transmittance over 90% in the visible range. • Incorporating oxygen into GTZO films suppresses oxygen vacancy formation, resulting in a reduction of generated free carriers. - Abstract: Ga–Sn–Zn–O (GTZO) thin films were deposited on glass substrates via the radio-frequency (RF) magnetron sputtering method at room temperature. The target for the GTZO film deposition was a single GaSnZnO pellet. Various oxygen gas content levels in the sputtering gas ambient (0, 3.8, 7.4, and 10.7%) were used in the deposition experiments. The resistivity of GTZO films decreased from 78 to 19.5 Ω cm when the oxygen content was decreased from 10.7 to 0%. The carrier concentration significantly decreased from 1.81 × 1017 cm−3 to 5.98 × 1015 cm−3 when the oxygen content was increased from 0 to 10.7%. Incorporating oxygen into GTZO films suppresses oxygen vacancy formation, resulting in a reduction of generated free carriers. The mobility increases rapidly with increasing oxygen pressure. The highest mobility of 13.3 cm2/V s was obtained at a carrier concentration of 5.98 × 1015 cm−3
[en] Highlights: • A method combining arc plasma evaporation and high pressure torsion is developed. • Bulk Mg based nano-composite containing dispersed MgO is successfully prepared. • Bulk Mg composite shows better H-storage properties over the ultrafine Mg powder. • MgO improves the hydrogen sorption kinetics of the bulk Mg nano-composite. - Abstract: A nanostructured Mg based bulk material containing Mg nano-grains and dispersed nanosized MgO was prepared through arc plasma method followed by high pressure torsion (HPT). In comparison to pure Mg ultrafine powders prepared using only arc plasma method, the hydrogenation enthalpy was slightly increased and the absorption activation energy was reduced through the HPT treatment. The structure refinement and the fragmentation of the MgO layer induced by the HPT account for the improved hydrogen sorption thermodynamic and kinetic properties
[en] Highlights: • Preparation of Tm3+ doped fluoride-phosphate (FP) glasses. • Studies of density, RI, IR, UV–vis and fluorescence spectra of the prepared glasses. • The change of glass from metaphosphate (PO3−)n to P2(O,F)7 and P(O,F)4. • Correlation of UV–vis band with nephelauxetic parameter. • The low multiphonon relaxation rate in oxyfluorophosphate glasses. -- Abstract: The present paper reports the preparation of Tm3+ doped fluoride-phosphate (FP) glasses in the system of (100-18n) Ba(PO3)2 × n (2.0 MgF2 + 9.6 CaF2 + 6.4 AlF3), where n = 0.00, 2.00, 4.00 and 5.17. Various physical properties namely density, refractive index with special emphasis on the infrared (IR), ultraviolet–visible (UV–vis) absorption and fluorescence spectra of the prepared glasses has been systematically studied. The spectral studies reveal that upon addition of fluoride, the structure of the glass changes from metaphosphate (PO3−)n to P2(O,F)7 and P(O,F)4 in combination with the formation of Al(O,F)6, [AlF6]3− and [AlF4]−. The position of UV–vis absorption band has been correlated with quantitative calculation of nephelauxetic parameter and covalent bonding characteristics of the host. Appearance of two emission bands at ∼650 nm and ∼790 nm corresponds to 1G4 → 3F4 and 3H4 → 3H6 transitions, respectively. It is evident from the IR study that the fluorescence phenomena are expedited by the low multiphonon relaxation rate in oxyfluorophosphate glasses owing to their high intense low phonon energy (∼595 cm−1), which is very close to that of the fluoride glasses (500–600 cm−1)
[en] Highlights: • CdS/ZnS/Ru film catalyst is able to produce H2 under visible light. • The photocatalyst is capable of both H2 production and organic degradation. • ZnS layer improves the photoreactivity and stability of the CdS film. • CdS/ZnS/Ru in formic acid produces 123 mmol H2 and removes 1.9 g COD/m2-h. -- Abstract: A layered CdS/ZnS catalyst film was synthesized on glass using the stepped chemical bath deposition method. The film catalyst was shown as visible light-driven photocatalyst capable of producing H2 under visible light. The ZnS outer layer helped suppress the recombination of photo-generated electron–hole pairs on the CdS base layer, leading to faster H2 generation. The use of the ZnS layer also greatly improved the stability of the catalyst film and prevented the leaching of Cd2+ from the CdS layer. Deposition of Ru on the catalyst film further increased its photoreactivity for H2 production. The photocatalyst was effective in H2 production together with the degradation of model organic substances, such as formic acid, methanol, and ethanol. The greatest H2 production rates were achieved using the CdS/ZnS/Ru film in the formic acid solution at 123 μmol/m2-h under visible light and 135 mmol/m2-h under the simulated solar light. The corresponding theoretical reduction rates of chemical oxygen demand (COD) were 1.9 and 2.1 g/m2-h, respectively. As the multilayer CdS/ZnS/Ru film catalyst can be easily separated from water, it has a great potential for simultaneous photocatalytic hydrogen generation and organic wastewater treatment using solar energy
[en] Highlights: • Li_2TiO_3 nanopowders are prepared at 600 °C by using high-energy ball milling route. • The average particle size of Li_2TiO_3 powders is 86.7 nm. • Decreasing particle size of powders decreases the sintering temperature of ceramics. • Li_2TiO_3 ceramics are obtained at 1000 °C by using nanopowders as a precursor. • Increasing density will increase microwave dielectric properties of ceramics. - Abstract: In this study, Li_2TiO_3 nanopowders were synthesized via a high-energy ball-milling process followed by calcinations and Li_2TiO_3 ceramics were fabricated by solid-state reaction. The microstructure and microwave dielectric properties of Li_2TiO_3 ceramics were also investigated systematically. Li_2TiO_3 nanopowders with an average particle size of 86.7 nm were derived at 600 °C for 2 h. X-ray diffraction patterns exhibited that single monoclinic structure of the Li_2TiO_3 ceramics were obtained at an optimum sintering temperature of 1000 °C for 2 h by using low temperature synthesis nanopowders as a precursor. The samples of Li_2TiO_3 ceramics with grain sizes in the range of 1.5–5.0 μm showed dense microstructures and excellent microwave dielectric properties (ε_r = 16.4, Q × f = 54,326 GHz, τ_f = 27.4 ppm/°C). All these results illustrated that high-energy ball-milling method is a simple and practical route to produce Li_2TiO_3 ceramics for microwave applications
[en] Highlights: • ZnO/Fe_2O_3 tubular structure was prepared via photochemical deposition at RT. • The composites show a great improvement in photocatalytic characteristics. • The possible reasons of photocatalytic performance of composites were researched. • The formation mechanism of ZnO/Fe_2O_3 tubular structure was discussed. - Abstract: Fe_2O_3 nanoparticles were grown on ZnO nanorods (NRs) to form ZnO/Fe_2O_3 nanotube (NT) composites via photochemical deposition under ultraviolet light irradiation at a room temperature. Fe"3"+ ions in the solution preferentially adhere to the metastable Zn-rich (0 0 0 1) polar surfaces in ZnO NRs, which leading to the formation of ZnO/Fe_2O_3 NTs. ZnO/Fe_2O_3 NT nanocomposites show a great improvement in photocatalytic characteristics compared with the bare ZnO NRs. It can be inferred that the enhanced photocatalytic performance of ZnO/Fe_2O_3 is benefit from the synergistic effect of ZnO and Fe_2O_3 semiconductors
[en] Highlights: • We have studied influence of Sb-doping and Ge-doping for thermoelectric properties of Mg_2Si. • Mg_2Si and Sb doped Mg_2(Si_0_._9_5Ge_0_._0_5) were synthesized using spark plasma sintering equipment. • The Mg_2Si samples were analyzed by XRF, XRD, SEM and Hall measurement. • The ZT value of Sb0.23 at%-doped Mg_2(Si_0_._9_5Ge_0_._0_5) was 0.74 at 756 K. - Abstract: Magnesium silicide (Mg_2Si) has recently attracted much interest as an n-type thermoelectric (TE) material for converting waste heat into electric power. The objective of this work was to reveal a mechanism to increase the thermoelectric properties of Mg_2Si by Sb-doping and Ge-doping. Generally, Mg_2Si is synthesized by all-molten method. However, this synthesis method has some problems, for example, mass defects of Mg for Mg_2Si composition caused because the melting point of Mg_2Si is very close to the boiling point of Mg. In this study, we tried to synthesize high purity Mg_2Si from Mg and Si alloyed with a dopant (Sb, Ge) by spark plasma sintering (SPS). The Ge-doped samples had a higher ZT value than the ZT value of the Sb-doped sample of the same concentration without Ge because the thermal conductivity of the former was lower. The maximum ZT value of Sb0.23 at%-doped Mg_2(Si_0_._9_9_5Ge_0_._0_5) was 0.74 at 756 K