Comparison of the temperature-dependent electronic structure of the perovskites La0.65A0.35MnO3 (A=Ca,Ba)

The local metallicity of gadolinium doped compound semiconductors

The local metallicities of Hf(0.97)Gd(0.03)O(2), Ga(0.97)Gd(0.03)N, Eu(0.97)Gd(0.04)O and EuO films were studied through a comparison of the findings from constant initial state spectroscopy using synchrotron light. Resonant enhancements, corresponding to the 4d → 4f transitions of Eu and Gd, were observed in some of the valence band photoemission features. The resonant photoemission intensity enhancements for the Gd 4f photoemission features are far stronger for the more insulating host systems than for the metallic system Eu(0.96)Gd(0.04)O. The evidence seems to suggest a correlation between the effective screening in the films and the resonant photoemission process.

In situ x-ray reflectivity studies of dynamics and morphology during heteroepitaxial complex oxide thin film growth

We present a method, based on refraction effects in continuous, stratified media, for quantitative analysis of specular x-ray reflectivity from interfaces with atomic-scale roughness. Roughness at interfaces has previously been incorporated into this framework via Fourier transform of a continuous height distribution, but this approach breaks down when roughness approaches the atomic scale and manifests discrete character. By modeling the overall roughness at interfaces as a convolution of discrete and continuous height distributions, we have extended the applicability of this reflectivity model to atomic-scale roughness. The parameterization of thickness and roughness enables quantitative analysis of time-resolved in situ reflectivity studies of thin film growth, modeling step-flow, layer-by-layer and three-dimensional growth within a single framework. We present the application of this model to the analysis of anti-Bragg growth oscillations measured in situ during heteroepitaxial growth of La(0.7)Sr(0.3)MnO(3) on [Formula: see text] SrTiO(3) at different temperatures and pressures, and discuss the evolution of surface morphology.