Shubin Qin

Formation mechanism of black LiTaO3 single crystals through chemical reduction

Lithium tantalate (LiTaO3, LT) wafers of different colors were prepared through chemical reduction of regular congruent LT wafers. Samples with different colors corresponding to different annealing temperatures were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and measurements of the Curie temperature and density. It was found that chemical reduction does not influence the basic LT structure. The Ta charge state change due to chemical reduction was found to be the main reason for the formation of black LT wafers.

111) Twinned BaTiO3 microcrystallites

We report here the controlled synthesis of (111) twinned BaTiO3 microcrystallites, which are widely known for their (110) ferroelectric twins. This (111) twinned structure was obtained through a composite hydroxide mediated process by using amorphous TiO2 powders. A twin assisted re-entrant growth model is proposed to account for the microstructural aspects determined. It is considered that the (111) twins originate from the Ti–O octahedra of the amorphous TiO2 powders. The role of oriented aggregation is also discussed.