Dielectric Properties of Ca Doping α-BZN Ceramics

Abstract

Bi_1.5-δCa_δZnNb_1.5O₆O′ (0≤δ≤0.3) ceramics samples were prepared by conventional solid-state reaction methods. The effect of Ca²⁺ doping on dielectric properties, crystal chemistry characteristics and relaxor behavior of α-BZN pyrochlore were investigated. The dielectric constant decreases with increasing Ca content. The bond valance calculations revealed the dielectric constant was proportional to bond valance sum of O′ anions. When δ = 0, the dielectric relaxation is attributed to hopping of A-site cations, however, when δ > 0, the declining relaxor behavior is closely related to the increasing A-O′ bond valance, the change from perfect octahedral to regular cube.

Keywords:

• α-BZN; dielectric properties; relaxor behavior; 48f oxygen coordinate x

Funding

The work was supported by National Natural Science foundation of China under Grant No. 11074203 and Z2009-1-61009, the Chun Hui project of the Education of China under Grant No. Z2011077. the graduate innovation foundation of Xihua University under Grant No. YCJJ2015113, No. YCJJ2014046, No. YCJJ2014049, and No. YCJJ201405.