Crystal structure and microwave dielectric properties of Ba 4Nd9.33Ti18O54 ceramics with Ca 0.61Nd0.26TiO3 addition

Abstract

Effects of Ca0.61Nd0.26TiO3 (CNT) addition on crystal structure and microwave dielectric properties of Ba 4Nd9.33Ti18O54 (BNT) ceramics had been investigated. Only tungsten bronze type phase was formed when CNT addition (x) was less than 0.4. While, a secondary phase Nd2Ti 2O7 was observed when 0.4 ≤ × ≤ 0.8. As CNT addition increasing, the dielectric constant increased steadily, and temperature coefficient of resonant frequency had less change. Qf value firstly increased sightly, and decreased gently with further increase of CNT addition. The BNT ceramics exhibited high ε (∼80), high Qf value (> 9000 GHz) and relative low temperature coefficient (∼50 ppm/°C) when CNT addition (x) was not beyond 0.4. The relationships between the crystal structure, tolerance factor and microwave dielectric properties had been also discussed. ©2009 The Ceramic Society of Japan. All rights reserved.