A study of sol-gel derived Sr_2(AITa)O_6 by Raman spectroscopy

摘要

Among the dielectric materials of current interest the cubic ternary system Sr2(AlTa)C>6 (SAT) is particularly attractive since it exhibits an excellent lattice and thermal expansion match with Y-123, Y-124, Bi-2212, Bi-2223 and Tl-1223 superconductors. Its low dielectric constant and low tan <5 favours its use in microwave device applications. Thin films of high Tc oxides deposited on SAT ceramics are chemically non-reactive at the interface between the films and the ceramic material. SAT ceramic samples were identified to have double cell cubic perovskite structure with lattice parameter a = 0.77805 nm and melting temperature 1900 °C [1]. Thin films of SAT and multilayers of SAT/YBCO (YBa2Cu3O7) were grown on (001) LaAlO3 and (001) MgO substrates by pulsed laser deposition [2], SAT was first prepared by Brandle and Fratello [3] in a study of potential substrate materials for the growth of high temperature superconductor films.