Preparation of Pyrochlore Potassium Tantalate Thin Films on Ta/ITO Glass via Mild Hydrothermal Growth

Abstract

Potassium tantalate with perovskite structure (KTaO₃) is an incipient ferroelectric material that has promising functions in electromechanical and sensing sectors. Potassium tantalate with pyrochlore structure (K₂Ta₂O₆) appears promising in a photocatalystic field. Potassium tantalate powders and bulks were fabricated at high temperature such as over 400°C from Ta₂O₅ and KOH. A sheet of tantalum was hard to react with potassium hydroxide in the mild hydrothermal condition at 100–150°C and low alkaline concentrations (0–2 M). Pyrochlore potassium tantalate film was synthesized with a mild hydrothermal method (100–150°C) at short reaction time by using a sputtered tantalum substrate on ITO glass. Synthesis of this film employed significantly low concentrations of KOH solution (0.1–1 M). The potassium tantalate film fabricated by the hydrothermal condition of 0.5 M-KOH solution, 100°C and 3 h reaction time was a smooth surface and became transparent. The particle size of this film was 150 nm.