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 (0-2M). 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 150nm. © 2010 The Japan Institute of Metals.