Structure evolution and piezoelectric properties across the morphotropic phase boundary of Sm-substituted BiFeO3 ceramics

The evolution of structure, ferroelectric, and piezoelectric properties in Bi 1−x Sm x Fe 0.99 Ti 0.01 O 3 ceramics was extensively investigated within the entire morphotropic phase boundary region with 0 ≤ x ≤ 0.20. A sequential phase transition of R3c-Pna2 1 -Pbnm with increasing Sm content was revealed by Rietveld refinement of the X-ray diffraction data together with the macroscopic ferroelectric measurements. Both ferroelectric and piezoelectric properties showed a great enhancement in the vicinity of the R3c/Pna2 1 (polar-to-polar) phase boundary, which should be caused by the field-induced phase transition between these two phases. Such field-induced phase transition might be essentially accompanied by a change of magnetic state, which indicated a way of controlling magnetism by means of electric field.