Structural, spectroscopic and microwave characterizations of (Sm sub(0.5)Y sub(0.5))Ti(Nb sub(1-x)Ta sub(x)) O sub(6) ceramics

Microwave dielectric ceramics of the type (Sm sub(0.5)Y sub(0.5))Ti(Nb sub(1-x)Ta sub(x))O sub(6) were prepared for x = 0, 0.2, 0.4, 0.6, 0.8 and 1 through the conventional solid state ceramic route. The ball-milled compositions were calcined at 1,250 degree C. The cylindrical pellets were sintered at temperatures between 1,385 and 1,450 degree C. The densities were determined by Archimedes method. The structure was analyzed using X-ray diffraction method. The microwave dielectric properties of the polished pellets were measured using cavity resonator method. The morphological studies were done using Scanning Electron Microscopy and Transmission Electron Microscopy. The Raman spectra were recorded and analyzed to confirm the structural change. The photoluminescence spectra were also taken and the emission lines were identified. A correlation study was done among the measured properties and parameters. Most of the samples have high dielectric constant, high quality factor and low temperature coefficient of resonant frequency and hence suitable for microwave applications.