Crystal Structural Characterization and Microwave Dielectric Properties of Ca(Ta2-xNbx)O6 Ceramics
作者： Akinori Kan , Hirotaka Ogawa
DOI: 10.1143/JJAP.47.7716
关键词: Crystal 、 Powder diffraction 、 Columbite 、 Mass fraction 、 Crystal structure 、 Mineralogy 、 Analytical chemistry 、 Materials science 、 Phase (matter) 、 Ceramic 、 Orthorhombic crystal system
摘要: The effects of Nb substitution for Ta on crystal structures and the microwave dielectric properties Ca(Ta2-xNbx)O6 (CTN) ceramics were investigated in this study. X-ray powder diffraction (XRPD) patterns CTN with composition x ranging from 0 to 1 show a single phase, which corresponds an orthorhombic phase aeschynite-type structure (space group: Pnma), whereas those samples compositions higher than x=1.5 are indexable columbite-type Pbcn). In range 1.1–1.4, two phases coexist ceramics. As covalencies ceramics, Ca–O Ta/Nb–O bonds strongly depend structure. addition, significantly varied at 1.5, depending weight fraction aeschynite columbite phases. result, showed Qf 102,500 GHz er 16 τf -56 ppm/°C. Moreover, near zero value was obtained x=1.25 because coexistence
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