The Experts below are selected from a list of 162 Experts worldwide ranked by ideXlab platform
Myunghwan Whangbo - One of the best experts on this subject based on the ideXlab platform.
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nonequivalent spin exchanges of the hexagonal spin lattice affecting the low temperature magnetic properties of rino3 r gd tb dy importance of spin orbit coupling for spin exchanges between rare earth cations with nonzero orbital moments
Inorganic Chemistry, 2018Co-Authors: Elijah E Gordon, Xiyue Cheng, Sangwook Cheong, Shuiquan Deng, Myunghwan WhangboAbstract:Rare-earth Indium Oxides RInO3 (R = Gd, Tb, Dy) consist of spin-frustrated hexagonal spin lattices made up of rare-earth ions R3+, where R3+ = Gd3+ (f7, L = 0), Tb3+ (f8, L = 3), and Dy3+ (f9, L = 5). We carried out DFT calculations for RInO3, including on-site repulsion U with/without spin–orbit coupling (SOC), to explore if their low-temperature magnetic properties are related to the two nonequivalent nearest-neighbor (NN) spin exchanges of their hexagonal spin lattices. Our DFT + U + SOC calculations predict that the orbital moments of the Tb3+ and Dy3+ ions are smaller than their free-ion values by ∼2μB while the Tb3+ spins have an in-plane magnetic anisotropy, in agreement with the experiments. This suggests that the f orbitals of each R3+ (R = Tb, Dy) ion are engaged, though weakly, in bonding with the surrounding ligand atoms. The magnetic properties of GdInO3 with the zero orbital moment are adequately described by the spin exchanges extracted by DFT + U calculations. In describing the magnetic pr...
A I Kulak - One of the best experts on this subject based on the ideXlab platform.
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structural optical and photoelectrochemical properties of nanocrystalline tio2 in2o3 composite solids and films prepared by sol gel method
Journal of Physical Chemistry B, 2001Co-Authors: S K Poznyak, A I KulakAbstract:Nanocrystalline titanium and Indium Oxides and TiO2−In2O3 composites have been prepared by sol−gel technique using concentrated hydrous titanium dioxide and Indium hydroxide sols. Structure, optical, and photoelectrochemical properties of the composites with different molar ratios of TiO2 to In2O3 have been studied. The binary oxide films and xerogels annealed at temperatures from 200 to 700 °C have a nanocrystalline structure without the chemical interaction between the Oxides. However, there is a strong mutual influence of the components of the binary oxide systems, during their annealing which manifests itself in thermogravimetry and differential scanning calorimetry measurements and in a marked effect on the oxide crystallite size. Highly transparent TiO2−In2O3 films fabricated by spin-coating technique exhibit extreme dependencies of the various optical and photoelectrochemical properties on the film composition. The band gap edge of the composite films is blue-shifted, as compared with that of singl...
S Mcgill - One of the best experts on this subject based on the ideXlab platform.
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Magnetochromic effect in multiferroicRIn1−xMnxO3(R=Tb, Dy)
Physical Review B, 2015Co-Authors: Peng Chen, B. S. Holinsworth, K. R. O'neal, T. V. Brinzari, Dipanjan Mazumdar, Craig V. Topping, S-w. Cheong, J. Singleton, Xuan Luo, S McgillAbstract:We combined high field magnetization and magneto-optical spectroscopy to investigate spin-charge coupling in Mn-substituted rare-earth Indium Oxides of chemical formula RIn₁₋xMnxO₃ (R=Tb, Dy). The edge states, on-site Mn³⁺d to d excitations, and rare-earth f-manifold excitations all track the magnetization energy due to dominant Zeeman interactions. The field-induced modifications to the rare-earth excitations are quite large because spin-orbit coupling naturally mixes spin and charge, suggesting that the next logical step in the design strategy should be to bring spin-orbit coupling onto the trigonal bipyramidal chromophore site with a 4 or 5d center.
Pier Luigi Gentili - One of the best experts on this subject based on the ideXlab platform.
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hydrogen production from water by photolysis sonolysis and sonophotolysis with solid solutions of rare earth gallium and Indium Oxides as heterogeneous catalysts
Sustainability, 2015Co-Authors: Marta Penconi, Federico Rossi, F Ortica, Fausto Elisei, Pier Luigi GentiliAbstract:In this work, we present the hydrogen production by photolysis, sonolysis and sonophotolysis of water in the presence of newly synthesized solid solutions of rare earth, gallium and Indium Oxides playing as catalysts. From the experiments of photolysis, we found that the best photocatalyst is the solid solution Y0.8Ga0.2InO3 doped by sulphur atoms. In experiments of sonolysis, we optimized the rate of hydrogen production by changing the amount of water, adding ethanol and tuning the power of our piezoelectric transducer. Finally, we performed sonolysis and sonophotolysis experiments in the presence of S:Y0.8Ga0.2InO3 finding a promising synergistic effect of UV-visible electromagnetic waves and 38 kHz ultrasound waves in producing H2.
U Givan - One of the best experts on this subject based on the ideXlab platform.
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compositional disorder and transport peculiarities in the amorphous Indium Oxides
Physical Review B, 2012Co-Authors: U Givan, Z OvadyahuAbstract:We present results of the disorder-induced metal-insulator transition (MIT) in three-dimensional amorphous Indium-oxide films. The amorphous version studied here differs from the one reported by Shahar and Ovadyahu [Phys. Rev. B 46, 10917 (1992)] in that it has a much lower carrier concentration. As a measure of the static disorder we use the dimensionless parameter ${k}_{F}\ensuremath{\ell}$. Thermal annealing is employed as the experimental handle to tune the disorder. On the metallic side of the transition, the low temperature transport exhibits weak-localization and electron-electron correlation effects characteristic of disordered electronic systems. These include a fractional power-law conductivity versus temperature behavior anticipated to occur at the critical regime of the transition. The MIT occurs at a ${k}_{F}\ensuremath{\ell}\ensuremath{\approx}0.3$ for both versions of the amorphous material. However, in contrast with the results obtained on the electron-rich version of this system, no sign of superconductivity is seen down to $\ensuremath{\approx}$0.3 K even for the most metallic sample used in the current study. This demonstrates that using ${k}_{F}\ensuremath{\ell}$ as a disorder parameter for the superconductor-insulator transition (SIT) is an ill defined procedure. A microstructural study of the films, employing high resolution chemical analysis, gives evidence for spatial fluctuations of the stoichiometry. This brings to light that, while the films are amorphous and show excellent uniformity in transport measurements of macroscopic samples, they contain compositional fluctuations that extend over mesoscopic scales. These, in turn, reflect prominent variations of carrier concentrations thus introducing an unusual type of disorder. It is argued that this compositional disorder may be the reason for the apparent violation of the Ioffe-Regel criterion in the two versions of the amorphous Indium oxide. However, more dramatic effects due to this disorder are expected when superconductivity sets in, which are in fact consistent with the prominent transport anomalies observed in the electron-rich version of Indium oxide. The relevance of compositional disorder (or other agents that are effective in spatially modulating the BCS potential) to other systems near their SIT is discussed.