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Structure and Microwave Dielectric Properties of Solid Solution in SrLaAlO 4 ‐Sr 2 TiO 4 System
Author(s) -
Mao Min Min,
Chen Xiang Ming,
Liu Xiao Qiang
Publication year - 2011
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.1551-2916.2011.04627.x
Subject(s) - solid solution , dielectric , analytical chemistry (journal) , enthalpy , microwave , materials science , diffraction , lattice constant , x ray crystallography , lattice (music) , crystallography , mineralogy , chemistry , thermodynamics , optics , physics , optoelectronics , chromatography , quantum mechanics , acoustics , metallurgy
Ceramics in (1− x ) SrLaAlO 4 ‐ x Sr 2 TiO 4 system were synthesized in the entire range of 0 ≤ x ≤ 1 by a standard solid‐state reaction method. X‐ray diffraction patterns revealed a single solid solution phase Sr 1+ x La 1− x Al 1− x Ti x O 4 with K 2 NiF 4 ‐type structure. The cell refinement showed the linear variation of lattice parameters a, c, and cell volume. With increasing x , ε r increased from 17.6 to 31.0, whereas τ f was tuned from −32 to 122 ppm/ o C. The Qf value first increased and then decreased with increasing x due to the result of competition balance between the effect of layer mismatch and interlayer polarization. The degradation of Qf value in the vicinity of x = 0.2 could be attributed to the compositional fluctuation and inhomogeneity originated from the positive mixing enthalpy Δ H mix , which could be confirmed by TEM observation. The best combination of microwave dielectric characteristics was achieved at x = 0.4: ε r = 18.5, Qf = 95 000 GHz, τ f = −8.9 ppm/ o C.