Processing and microwave dielectric properties of Sr5Ta4TiO17 ceramics

Abstract

Abstract Sr5Ta4TiO17 ceramics was processed via solid state mixed oxide sintering route. X-ray diffraction revealed single phase formation of Sr5Ta4TiO17 ceramics that crystallized into an orthorhombic crystal structure with a space group Pnnm with lattice parameters of a = 5.681 Å, b = 32.542 Å and c = 3.968 Å, refined by the least squares method. The unit cell density (ρth) was 6.71 g/cm3. The microstructure consisted of plate-like grains and the average size was increased from 2 μm to 5 μm with an increase in sintering temperature from 1450 °C to 1575 °C. Optimum microwave dielectric properties, i.e. єr ~ 66,Qufo ~ 8500 GHz and τf ~ 180 ppm/°C, were achieved for Sr5TaTiO17 ceramics sintered at 1550 °C for 4 h.