Effects of sintering temperatures on dielectric properties, vibrational modes and crystal structures in Ba[Sn_(0.32)Zn_(0.68/3)Nb_(1.36/3)]O_3 ceramics

摘要

Ba[Sn_(0.32)Zn_(0.68/3)Nb_(1.36/3)]O_3 ceramics were sintered at different temperatures by conventional solid-state sintering method so as to clarify the effects of the sintering temperatures on vibrational modes, crystal structures and dielectric properties. Lattice vibrational spectra, obtained by Raman spectroscopy and Fourier transform far-infrared reflection (FTIR) spectroscopy, show the relationship among polar phonon modes, crystal structures and dielectric properties in Ba[Sn_(0.32)Zn_(0.68/3)Nb_(1.36/3)]O_3 ceramics as a function of sintering temperatures. Raman and FTIR active modes were indicated according to the group theory. The results demonstrate that dielectric constant and temperature coefficient of capacitance are closely related to Raman modes at 480 cm~(-1); dielectric loss values are closely connected with full width at half-maximum of A_(1g)(Nb) and E_g(O) active modes with increasing temperatures, which can also be proved by FTIR.