Enhanced Piezoelectric Constant of (1-x)BiFeO₃–xBiCoO₃ Thin Films Grown on LaAlO₃ Substrate

Abstract

Thin films of a rhombohedral-tetragonal solid solution (1- x )BiFeO 3 – x BiCoO 3 with x = 0–0.30 were prepared by chemical solution deposition on LaAlO 3 (001) and (La 0.5 ,Sr 0.5 )CoO 3 (001)/LaAlO 3 (001) substrates. A BiCoO 3 -type tetragonal structure with a large c / a of 1.23 was grown adjacent to the substrate whereas a BiFeO 3 -type rhombohedral one was grown on the tetragonal phase. Co substitution in the rhombohedral phase led to enhancement of piezoelectric constant and d 33 reached 100 pm/V, almost double that of BiFeO 3 .