Crystal structure and electrical properties of (Li, Ce, Nd)-multidoped CaBi2Nb2O9 high temperature ceramics.

(Li, Ce, and Nd)-multidoped CaBi 2 Nb 2 O 9 (CBN) Aurivillius phase ceramics were prepared via a conventional solid-state sintering route. The crystal structure including bond lengths and bond angles, microstructure, dielectric constant, DC resistivity, and piezoelectric properties were systematically investigated. Rietveld-refinements of X-ray results indicated that small quantity of (Li, Ce, Nd) doping (< 2.5 mol%) increases orthorhombic distortion, because of the smaller ionic radii of doping ions. However, orthorhombic distortion obviously decreased with increasing (Li, Ce, Nd) doping concentration from 5 to 25 mol%. The replacement of asymmetric A-site Bi 3+ with 6s2 lone pair electrons by symmetric Li + , Ce 3+ and Nd 3+ ions decreased the orthorhombic distortion. The morphologies and electrical properties of sintered ceramics were tailored by the introducing (Li, Ce, Nd) multi-dopants. The improvement of piezoelectric properties of modified-CBN ceramics were attributed to decreasing grain sizes and morphotropic phase boundary (MPB). Ca 0.85 (Li 0.5 Ce 0.25 Nd 0.25 ) 0.15 Bi 2 Nb 2 O 9 (CBNLCN-15) ceramics had optimum properties, and d 33 and T c values were found to be ~ 13.1 pC/N and ~ 900 °C, respectively. [ABSTRACT FROM AUTHOR]