Influence of Lanthanum Concentration on Properties of BLT Electroceramics

摘要

Results of fabrication and study of Ba_(1-x)La_xT_(1-x/4)O_3 (BLT) ceramics for x within the range 0.001 ≤ x ≤ 0.004 are reported in the present paper. BLT ceramics have a structure based on ABO_3-type perovskite, and its properties strongly depend on the chemical composition. The interrelated semiconductor and ferroelectric properties of La-doped BaTiO_3 ceramics were considered for describing its electrical properties. Dielectric properties were studied in frequency domain by impedance spectroscopy with a Quadtech 1920-type precision LCR meter at room temperature T=RT. It was found that the concentration of lanthanum increases the average crystalline grain size decreases. A decrease in mean dimension of crystallites and a decrease in volume of the elementary cell as well as an increase in calculated density was observed.