Novel high εr MNdTiNbO7 (M = Ca, Sr) microwave dielectric ceramics: preparation, phase composition, microstructure, and dielectric performance

作者：Qu, Xin; He, Sen; Li, Qing; Deng, Shan; Xiao, Yaqi; He, Guoqiang; Liu, Kaiyang; Wu, You; Liang, Jun; Chen, Xiuli^*; Zhou, Huanfu^*

来源：Journal of Materials Science: Materials in Electronics , 2022, 33(21): 17295-17305.

DOI：10.1007/s10854-022-08606-x

• SINTERING BEHAVIOR
• LATTICE ENERGY
• BOND IONICITY
• VALENCE
• ND
• RE
• SM

MNdTiNbO7 (M = Ca, Sr) ceramics were prepared by a conventional solid-state reaction method. Single-phase dense CaNdTiNbO7 (CNTN) ceramic was obtained at 1400 degrees C and displayed outstanding microwave dielectric properties of Q x f = 6710 GHz, tau(f) = 205 ppm/degrees C, and epsilon(r) = 65.1. While the excellent microwave dielectric properties of Q x f = 8088 GHz, tau(f) = 305 ppm/degrees C, and epsilon(r) = 56.5 were obtained for the SrNdTiNbO7 (SNTN) ceramic at 1375 degrees C. The GSAS analysis software was used to investigate the ion occupancy of the ceramic samples and the changes in their phase structure. When the sintering temperature was 1400 degrees C, the lattice energy and packing fraction of the CNTN ceramic reached the maximum values of 41,779.7 kJ/mol and 65.35%. The CNTN ceramic resistance is mainly influenced by the grain boundaries. The substitution of Ta for Nb could adjust the tau(f) value of CNTN ceramic. As x = 0.8, the tau(f) values of CaNdTi(Nb1-xTax)O-7 ceramics sintered at 1400 degrees C would be decreased from + 205.18 to + 20.27 ppm/degrees C.

• 单位
  桂林理工大学