Many of the transition metal oxides (i.e. oxide materials where metal ions contain d-electrons) exhibit high catalytic activity and are widely used in industrial applications. A recent discovery of the possibility of using U 3 O 8 for the catalytic destruction of a range of environment pollutants has stimulated research aimed at investigating the connection between the catalytic activity of tra...

Certain niobium oxide (NbO , x ~ 2) materials are near insulating at room temperature fut undergo an "insulatorto-metal" transition near 800°C. A similar transition can be initiated at room temperature by applying an electric field. exceeding the "threshold" value, which depends on the oxygen concentration (x) of the NbOx. Metal-oxide threshold switch (MOTS) prototypes are obtained by applying ...

In this paper we report on the study of electrical switching in thin film MOM structures on the basis of transition metal oxides under AC conditions. The materials studied are Nb2O5, TiO2, and WO3, obtained by electrochemical oxidation of the metal, as well as MoO3, obtained by thermal deposition in vacuum. Transformations of dynamic switching characteristics with changes in temperature and fre...

We show why and how the spin state of transition-metal ions affects the thermoelectric properties of transition-metal oxides by investigating two perovskite-related oxides. In the A-site ordered cobalt oxide Sr3YCo4O10.5, partial substitution of Ca for Sr acts as chemical pressure, which compresses the unit cell volume to drive the spin state crossover, and concomitantly changes the magnetizati...

We investigate the electronic structure of carbon and nitrogen impurities, which are commonly incorporated during atomic-layer deposition of high-j oxides such as Al2O3 and HfO2. The impact on metal-oxide-semiconductor devices is assessed by examining formation energies, transition levels, and band alignment between the oxide and semiconductors such as GaN, Si, and III-As. Carbon introduces cha...

When pushing the gate dielectric thickness of metal-oxide-semiconductor (MOS) devices down to the subnanometer scale, the most challenging issue is the interface. The interfacial transition layers between the high-k dielectric/Si and between the high-k dielectric/gate metal become the critical constraints for the smallest achievable film thickness. This work presents a detailed study on the int...

We report measurements and analyses of resistivity, thermopower and thermal conductivity of polycrystalline samples of perovskite LaRh(1-x)Ni(x)O(3). The thermopower is found to be large at 800 K (185 µV K(-1) for x = 0.3), which is ascribed to the high-temperature stability of the low-spin state of Rh(3+)/Rh(4+) ions. This clearly contrasts with the thermopower of the isostructural oxide LaCoO...

The one-third paradigm of PBE0 density functional, PBE0-1/3, has shown to be a successful method for various properties. In this paper, the applicability of PBE0-1/3 is put into broader perspective for transition metals chemistry. As a comparative study, the performance of PBE0 and PBE0-1/3 has been assessed for geometries and vibrational frequencies of some transition metal hydrides and transi...

Several studies of the decohesion properties of various oxide/metal systems have been performed recently by ab initio calculations. However, the use of different computational methods, which involve diverse approximations, energy functionals, or calculation conditions, makes the identification of general trends difficult. In the present work, a broad range of interfaces between an ionic oxide A...

Comparison is made of the electronic structure of the little-studied layered transition metal oxide LiNbO2 with that of NaxCoO2, which has attracted tremendous interest since superconductivity was discovered in its hydrate. Although the active transition metal d states are quite different due to different crystal fields and band filling, both systems show a strong change of electronic structure...