7 research outputs found
The Structure of Ga-Sb-Se Glasses by High-Resolution X-Ray Photoelectron Spectroscopy
International audienceTo understand the unique physical properties of Ga-Sb-Se glasses, high-resolution X-ray photoelectron spectroscopy (XPS) studies are performed on representative compositions within the glass-forming region. The observed peaks in the valence band as well as in Ga, Sb, and Se core-level XPS spectra are related to the main structural building blocks of the covalent network. On the basis of disproportionality equations and quantitative XPS analysis, the Se-Se-Se fragments are shown to exist in the glasses with 65 and 68 at% of Se, whereas the samples with lower Se content are shown to contain a significant concentration of Se-Se bonds instead. Although the majority of Ga atoms are deemed to form fourfold coordinated units, the existence of Ga atoms in threefold coordination, those bonded to other metal, and forming Ga clusters of undissolved Ga are also plausible on the basis of Ga 3d XPS spectrum analysis. Partial or full destruction of antimony selenide pyramids is found in glasses with low Se content