Publication Date:
2011-05-28
Description:
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.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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