Effect of Ca²⁺ substitution on impedance and electrical conduction mechanism of Ba_1−xCa_xZr_0.1Ti_0.9O₃ (0.00≤x≤0.20) ceramics

详细信息    查看全文

• 作者：Tanusree Mondal^a ; Sayantani Das^b ; T. Badapanda^c ; T.P. Sinha^d ; P.M. Sarun^a ; ^{sarun.res@gmail.com}
• 关键词：Electroceramics ; Barium titanate&ndash ; zirconate ; Raman spectrum ; Impedance spectroscopy ; Dielectric relaxation ; ac-conductivity
• 刊名：Physica B: Condensed Matter
• 出版年：2017
• 出版时间：1 March 2017
• 年：2017
• 卷：508
• 期：Complete
• 页码：124-135
• 全文大小：2948 K
• 卷排序：508

文摘

The Ca modified Ba1−xCaxZr0.1Ti0.9O3 (BCZT) system for x=0.00–0.20 is synthesized by the high-temperature conventional solid state reaction method. The morphotropic phase boundary (MPB) between the tetragonal and cubic structure is obtained at room temperature for the composition x=0.15. The doping of Ca facilitates the enhancement of the homogeneity of microstructure and growth of the grain size. The phase transition is also confirmed by Raman spectroscopy. In order to explore the effect of Ca concentration variation on the conduction mechanism of BaZr0.1Ti0.9O3 (BZT) ceramic, the frequency dependent ac impedance spectroscopy technique is used at various temperatures. The effect of Ca doping on the electrical properties of BZT is clearly noticeable. The resistance of the grain (bulk) and the grain boundary is increased as a consequence of the increase in the activation energy of Ca substituted BZT samples. The enhanced resistivity of the Ca substituted BZT ceramics is explained in terms of the decrease in the mobility of the charge carriers associated with the lattice distortion. The electric modulus analysis reveals the enhanced capacitance of BCZT ceramics which is in good agreement with the results obtained from complex impedance analysis.