Thermal processing and properties of BaTi sub(4)O sub(9) and Ba sub(2)Ti sub(9)O sub(20) dielectric resonators

• Published in: Journal of materials science Vol. 34; no. 12; pp. 3021 - 3025
• Main Authors: Lin, Wen-Yi, Gerhardt, Rosario A, Speyer, Robert F, Hsu, Jen Yan
• Format: Journal Article
• Language: English
• Published: 01.01.1999
• ISSN: 0022-2461

Sn-doped and undoped barium titanates pressed powder pellets were sintered at 1360 and 1390 degree C for 5 h. Though batched to form Ba sub(2)Ti sub(9)O sub(20), a two-phase microstructure of BaTi sub(4)O sub(9) and TiO sub(2) formed from the undoped system. The dielectric constant at 6 GHz was 40 without SnO sub(2) additions. Doping with 1.64 mol% SnO sub(2) stabilized Ba sub(2)Ti sub(9)O sub(20) and formed a single-phase microstructure but resulted in higher porosity. Dilatometry studies implied that SnO sub(2) additions facilitated a greater fraction of reaction to occur in the solid state, causing a lower quantity of pore-filling fluid to form above 1317 degree C. As a result of the higher porosity, the dielectric constants and quality factors were also reduced.