Crystal structure and piezoelectric and magnetic properties of Bi1–xSmxFeO3 solid solutions

Resumo

The crystal structure and piezoelectric and magnetic properties have been studied in Bi_1‒xSm_xFeO₃ solid solutions with the compositions near the morphotropic boundary between rhombohedral and orthorhombic (Rh–Orh) phases. The coexistence areas of rhombohedral and antipolar orthorhombic phases, as well as the evolution of structural phases at the interface, have been established. A maximum piezoelectric signal is found for the two-phase composition with the dominating rhombohedral phase, and an increase in the piezoresponse is caused by the decreasing structural stability of the sample. The evolution of magnetic properties in Bi_1–xSm_xFeO₃ compounds has been elucidated depending on the substitutional ion concentration. The orthorhombic phase composites are the weak ferromagnetics with the residual magnetization of ~0.2 emu/g.