Cation diffusion in alkaline-earth oxides

Thermal Properties of Alkaline Earth Oxides

The heat capacities of MgO, CaO, SrO and BaO, reported in part I have been analysed in terms of the frequency spectrum of the lattice with the assumption that the effect of anharmonicity of the lattice may be neglected for T (@D / 3 ) . Following the usual procedure the n-th moments of the frequency spectrum with n = — 3, —2, — 1, 0, 1 to 6 were calculated from the experimental data. From the l...

Non – Nominal Value of the Dynamical Effective Charge in Alkaline – Earth Oxides

We calculate ab–initio the electronic states and the Born dynamical charge Z of the alkaline–earth oxides in the local–density approximation. We investigate the trend of increasing Z values through the series, using band–by–band decompositions and computational experiments performed on fake materials with artificially–modified covalence. The deviations of Z from the nominal value 2 are due to t...

Cation Ordering in Complex Oxides

Several recent papers have addressed the fundamental aspects of the stability and kinetics of ordering in complex oxides, and investigated systems where the properties are mediated by the degree of order. Cation ordering reactions have been shown to induce large alterations in the dielectric, ferroelectric, magnetic, and electronic response of many complex oxides. The majority of the cited publ...

Density Functional Theory Study of Surface and Bulk Nitrates of .-Al2O3 Supported Alkaline Earth Oxides

Introduction Alkaline earth oxides (AEOs) such as BaO have received considerable attention for their application in the lean-burn engine NOx storage/reduction (NSR) technology [1]. Previous experimental investigations have indicated that barium nitrate is the most stable form of the stored NOx in Ba-containing NSR catalysts. Two distinctive types of barium nitrates, Ba(NO3)2, i.e. “surface” and...

Diffusion in Oxides