Structure and microwave dielectric properties of La5-x Sr (x) Ti4+x Ga1-x O-17 ceramics

作者：Muhammad Raz; Iqbal Yaseen^*; Reaney Ian M

来源：Journal of Materials Science, 2015, 50(9): 3510-3516.

DOI：10.1007/s10853-015-8914-3

Single phase polycrystalline ceramics in the La5-x Sr (x) Ti4+x Ga1-x O-17 (x = 0-1) system with A(5)B(5)O(17) type layered perovskite structure were prepared via a mixed-oxide, solid state sintering route. X-ray diffraction revealed orthorhombic, Pnnm symmetry with Raman spectra consistent with this space group. The sintered ceramics exhibited a plate-like grain structure with a relative density, 94-97.5 %. The end member, La5Ti4GaO17 had epsilon (r) = 42.31, Q x f (o) = 17,093 GHz, tau (f) = -34.53 but tau (f) could be tuned close to zero by Sr and Ti substitution at the A- and B-sites, respectively. An optimum composition La4.5Sr0.5Ti4.5Ga0.5O17 was achieved at x = 0.5 with epsilon (r) = 51, Q x f (o) = 15,290 GHz and tau (f) = -2.2 ppm/C-o.

• 出版日期2015-5