Crystal structure–microwave dielectric property relations in Sm(Nb1−xTax)(Ti1−yZry)O6 ceramics

The effects of the Ta substitution for Nb and the Zr substitution for Ti on the microwave dielectric properties and crystal structure of Sm(Nb1−xTax)(Ti1−yZry)O6 ceramics were investigated in this study. The Sm(Nb1−xTax)TiO6 (x = 0–1) ceramics were single phase, whereas the limit of solid solutions for the SmTa(Ti1−yZry)O6 ceramics was y = 0.4. In the case of the Sm(Nb1−xTax)TiO6 ceramics, the dielectric constant and the temperature coefficient of resonant frequency were decreased, whereas the quality factor was increased by the Ta substitution for Nb. The maximum Q · f value was obtained when the SmTaTiO6 was synthesized, and the microwave dielectric properties are, ɛr = 37.6; τf = 24.2 ppm/°C; and Q · f = 24541 GHz. On the other hand, the dielectric constants of the SmTa(Ti1−yZry)O6 ceramics were decreased from 37.6 to 28.9, whereas the quality factor was increased from 24541 to 38320 GHz with increasing composition y from 0 to 0.4. The temperature coefficient of resonant frequency of the ceramics varied from 24.2 to −11.6 ppm/°C. A near zero temperature coefficient of resonant frequency results from the composition of y = 0.3 with a dielectric constant of 31.1 and Q · f value of 37481 GHz.