Fabrication of undoped near-monophase Ba2Ti9O20 via rapid thermal processing

Abstract

Rapid thermal processing of BaTiO3 and TiO2 pressed powders at 500 °C/min to 1250 °C for 2 h in an infrared furnace resulted in a mixture of Ba2Ti9O20, BaTi4O9, and TiO2. Further heat treatment at 1390 °C led to 96 vol% phase-pure Ba2Ti9O20 from an initial mixture devoid of any dopant. Heat treatment at rates decreasing to 5 °C/min facilitated agglomeration of TiO2. This, in turn, increased the diffusion distance required for reaction of BaTi4O9 and TiO2 to form Ba2Ti9O20.