The charge state of titanium ions in Pd‐doped Ti:CMAS glass and glass‐ceramics

Abstract

We have investigated the role of charge state of Ti in the electronic properties and structure of electrically conductive CMAS‐TiO2‐Pd glass and glass‐ceramics by X‐ray photoelectron spectroscopy, electron paramagnetic resonance, positron annihilation lifetime spectroscopy, and fluorescence spectroscopy. These studies suggest the concentration of Ti3+ ions was, at most, ~0.1 wt% in glass‐ceramics devitrified in the reducing atmosphere of forming gas; no other glass or glass‐ceramic samples exhibited measurable levels of Ti3+. The observed fluorescence at liquid nitrogen temperature in parent glasses and glass‐ceramics obtained in air is explained by UV‐induced charge‐transfer processes involving Ti4+ ions and oxygen surroundings. The X‐ray photoelectron spectroscopy data are correlated with rutile, anorthite, diopside, and titanite crystalline phases identified in Pd‐free and Pd‐doped Ti:CMAS glass‐ceramics earlier.

Study of the crystallization in fast sintered Na-rich plagioclase glass-ceramic

“…Fig. 5a presents the comparison of Al 2p signal of both samples having similar binding energy, which agrees well with typical values of sodium and calcium aluminosilicate feldspars (74.1-74.4 eV) [24,25], although binding energy for Al 2p signal slightly shifted (0.05 eV) in vitreous network. Fig.…”