Premium
Microwave Dielectric Properties of Ca 4 La 2 Ti 5− x ( Mg 1/3 Nb 2/3 ) x O 17 Ceramics
Author(s) -
Chen Guohua,
Di Jiechang,
Xu Huarui,
Jiang Minhong,
Yuan Changlai
Publication year - 2012
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2011.05004.x
Subject(s) - microstructure , materials science , analytical chemistry (journal) , ceramic , grain size , phase (matter) , mineralogy , doping , crystallography , chemistry , metallurgy , chromatography , optoelectronics , organic chemistry
Using the solid‐state ceramic route, Ca 4 La 2 Ti 5− x ( Mg 1/3 Nb 2/3 ) x O 17 (0 ≤ x ≤ 4) ceramics were prepared, and the phase purity, microstructure, and microwave dielectric properties were investigated. The XRD results suggest the formation of solid solutions for all studied compositions (0 ≤ x ≤ 4) and the unit cell volume increases linearly with x . The SEM results also show no evidence of secondary phase and doping ( Mg 1/3 Nb 2/3 ) at Ti site promotes the grain growth. The ε r of sintered ceramics decreases from 71.86 to 35.23, the Q × f value increases from 15 070 to 21 277 GHz and the τ f value varies from 125.2 to −16.7 ppm/°C with x increasing from 0 to 4. A near‐zero τ f (~1.62 ppm/°C) is achieved at x = 3 with ε r ~ 40.45 and Q × f ~ 19 123 GHz.