X-ray and electrical properties of Ba(Gd0.5Nb0.5)O3 ceramic
1University Department of Physics, V. K. S. University, Ara 802301, India
2University Department of Physics, T. M. Bhagalpur University, Bhagalpur 812007, India
3Department of Physics, Bose Institute, 93/1, A.P.C. Road, Kolkata 700009, India
Adv. Mater. Lett., 2012, 2 (1), pp 76-81
Publication Date (Web): Apr 08, 2012
Copyright © IAAM-VBRI Press
The complex perovskite oxide barium gadolinium niobate, Ba(Gd0.5Nb0.5)O3 (BGN) is synthesized by a solid-state reaction technique. The X-ray diffraction of the sample at room temperature shows a tetragonal phase. The scanning electron micrograph of the sample shows the average grain size of BGN ~ 1.92 mm. The frequency-dependent dielectric dispersion of BGN is investigated in the temperature range from 303 K to 463 K and in a frequency range from 50 Hz to 1 MHz by impedance spectroscopy. The logarithmic angular frequency dependence of loss peak is found to obey an Arrhenius law with activation energy of 0.70 eV. It is observed that: (i) the dielectric constant (e¢ ) and loss tangent (tan d) are dependent on frequency, (ii) the temperature of dielectric constant maximum shift toward lower temperature side, (iii) The scaling behavior of dielectric loss spectra suggests that the relaxation describes the same mechanism at various temperatures.
Dielectrics, electrical properties, X-ray diffraction, scanning electron micrographs.