The apparent difference in microwave dielectric properties of Ca3MZnGe3O12 (M = Zr, Sn) garnets originating from compression aria rattling effects

作者：Wang, Zhaohui; Fang, Weishuang; Tang, Ying; Xiang, Huaicheng; Li, Jie; Fang, Liang^*

来源：Journal of Materials Science: Materials in Electronics , 2022, 33(26): 21101-21110.

DOI：10.1007/s10854-022-08913-3

• BOND-VALENCE
• CRYSTAL-STRUCTURE
• CHEMICAL-BOND
• CERAMICS
• ZN
• CA
• DEPENDENCE
• BEHAVIOR
• SPECTRA
• SPINEL

Ca3MZnGe3O12 (M = Zr, Sn) ceramics crystallized in a cubic garnet structure (A(3)B(2)C(3)O(12)) with a space group of Ia-3d, and promising microwave dielectric properties with low coefficients of thermal expansion (alpha(L)) were obtained, namely, epsilon(r) = 10.5 and 9.3, Q x f = 79,700, and 96,040 GHz, tau(f) = - 36.1 and - 61.5 ppm /degrees C, and alpha(L) = 4.3 and 4.7 ppm/degrees C for Ca3ZrZnGe3O12 and Ca3SnZnGe3O12, respectively. Bond valence calculation reveals that Ca3SnZnGe3O12 exhibits a slight "compressed" effect at A-site and B-site with a slightly negative deviation (Delta epsilon(r) similar to - 1.01%) of the porosity corrected epsilon(r(corr) )from theoretical epsilon(r(C-M)) calculated by the C-M equation, while Ca3ZrZnGe3O12 shows a "rattling" effect at the A-site and C-site with a large positive Delta epsilon(r) similar to 15.8%, leading to a high epsilon(r), a more close to zero ac f and a lower Q x f value as compared to those of Ca3SnZnGe3O12. The relationship between structure and their intrinsic microwave dielectric properties was investigated by complex chemical bond theory and far-infrared reflectivity spectra.

• 单位
  广西大学; 桂林理工大学