Published online by Cambridge University Press: 15 February 2011
The thermal processing schedules necessary to form phase pure Ba2TigO20, with and without substitutional solid solution were investigated. Undoped compositions formed the compound most easily under rapid (500°C/min) heating rates, where diffusional agglomeration of the. TiO2 batch constituent was minimized. The compound formed most easily with minor (0.82%) substitutions of SnO2 and ZrO2 for TiO2. The solubility of Sn in Ba2Ti9O20 was higher than that of Zr. Extended heat treatment (16 vs. 6 h at 1390°C) resulted in volitalization of grain boundary liquid phase, leading to a more porous and slightly degraded resonators. The effects of dopant concentrations and soak periods at 1390°C on dielectric constants and temperature-dependent quality factors are reported.