Authors: Chuanling Diao Feng Shi
Publish Date: 2012/04/10
Volume: 47, Issue: 14, Pages: 5438-5445
Abstract
The BaNi07Zn031/3Nb2/3O3 solid solutions were sintered at 1450 1500 and 1550 °C for 3 h respectively by conventional solidstate sintering method so as to clarify the effect of the sintering temperatures on vibrational modes crystal structures and dielectric properties Ceramics were characterized by Xray diffraction XRD Raman spectroscopy and Fourier transform farinfrared reflection FTIR spectroscopy Space group and crystal symmetry of Pmbar3m were determined by XRD Lattice vibrational spectra obtained by Raman and FTIR spectroscopy show the correlation among polar phonon modes crystal structures and dielectric properties of BaNi07Zn031/3Nb2/3O3 ceramics as a function of the sintering temperatures The results demonstrate that the dielectric constant varepsilon r reaches a maximum value of 35713 at 1500 °C and is related to Raman shifts of the A1gO modes and the FWHM values of the EgO modes the temperature coefficient of the capacitance tau c which gradually increases from −6 × 10−6/°C to 0 is closely related to the Raman shifts of EgO modes and the dielectric loss values are closely connected with the full width at halfmaximum of EgO active modes and the Raman shifts of of the A1gO modes with the increasing temperatures FTIR shows that the dielectric properties are closely related to the farinfrared phonon modes Raman and FTIR active modes were indicated according to the group theory
Keywords: