Crystal structure and microwave dielectric properties of Ba₄Nd_9.33Ti₁₈O₅₄ ceramics with Ca_0.61Nd_0.26TiO₃ addition

Abstract

Effects of Ca_0.61Nd_0.26TiO₃ (CNT) addition on crystal structure and microwave dielectric properties of Ba₄Nd_9.33Ti₁₈O₅₄ (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 Nd₂Ti₂O₇ was observed when 0.4 ≤ x ≤ 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.