High permittivity and low dielectric loss analysis of lead free Sr1-xLax(Ti0.5Fe0.5)O3
来源期刊：中南大学学报(英文版)2013年第12期
论文作者：M. R. Shah A. K. M. Akther Hossain
文章页码：3363 - 3371
Key words：dielectric properties; solid state reaction; Sr titanate; X-ray diffraction
Abstract: The structural and electrical properties of lead free Sr1-xLax(Ti0.5Fe0.5)O3 (SLTFO) prepared by standard solid state reaction technique were studied. The X-ray diffraction analysis confirmed the formation of a single-phase cubic perovskite structure. The compositional dependence of lattice constant, density and microstructural studies show that they vary significantly with La3+ content. When measured at 10 kHz, all the compositions of SLTFO at room temperature exhibit a high permittivity (about 104) and low dielectric loss (about 10-3). SLTFO also display minimum dielectric loss within the lower and higher limits of frequency, indicating that the samples are of good quality. It is concluded from the calculated ac conductivity that the conduction is due to mixed polarons hopping. The complex impedance plot exhibits a tendency of forming a single semicircular arc for all compositions, which implies a dominance of grain boundary resistance on the impedance. Impedance parameters were determined by fitting the experimental data with Cole-Cole empirical formula. The results of the present experiment indicate that the lead free SLTFO materials with higher permittivity and lower dielectric loss have possible practical applications.
M. R. Shah1, A. K. M. Akther Hossain2
(1. Department of Physics, Primeasia University, Banani, Dhaka-1213, Bangladesh;
2. Department of Physics, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh)
Abstract:The structural and electrical properties of lead free Sr1-xLax(Ti0.5Fe0.5)O3 (SLTFO) prepared by standard solid state reaction technique were studied. The X-ray diffraction analysis confirmed the formation of a single-phase cubic perovskite structure. The compositional dependence of lattice constant, density and microstructural studies show that they vary significantly with La3+ content. When measured at 10 kHz, all the compositions of SLTFO at room temperature exhibit a high permittivity (about 104) and low dielectric loss (about 10-3). SLTFO also display minimum dielectric loss within the lower and higher limits of frequency, indicating that the samples are of good quality. It is concluded from the calculated ac conductivity that the conduction is due to mixed polarons hopping. The complex impedance plot exhibits a tendency of forming a single semicircular arc for all compositions, which implies a dominance of grain boundary resistance on the impedance. Impedance parameters were determined by fitting the experimental data with Cole-Cole empirical formula. The results of the present experiment indicate that the lead free SLTFO materials with higher permittivity and lower dielectric loss have possible practical applications.
Key words:dielectric properties; solid state reaction; Sr titanate; X-ray diffraction
