화학공학소재연구정보센터
Journal of Materials Science, Vol.46, No.7, 2077-2084, 2011
Structural and electrical properties of Ba(Sb1/2Nb1/2)O-3 ceramic
Lead-free perovskite Ba(Sb1/2Nb1/2)O-3 was prepared by conventional ceramic fabrication technique at 1200 A degrees C/5 h in air atmosphere. The crystal symmetry, space group and unit cell dimensions were determined from the experimental results using FullProf software whereas crystallite size and lattice strain were estimated from Williamson-Hall approach. XRD analysis of the compound indicated the formation of a single-phase monoclinic structure with the space group P2/m. EDAX and SEM studies were carried out to evaluate the quality and purity of the compound. Dielectric study revealed the frequency-dependent dielectric anomaly. To find a correlation between the response of the real system and idealized model circuit composed of discrete electrical components, the model fittings were presented using the impedance data. Complex impedance analyses suggested the dielectric relaxation to be of non-Debye type. The correlated barrier hopping model was employed to successfully explain the mechanism of charge transport in Ba(Sb1/2Nb1/2)O-3. The ac conductivity data were used to evaluate the density of states at Fermi level, minimum hopping length and apparent activation energy of the compound.