Electric-field-controlled magnetism due to field-induced transition of Pna21/R3c in Bi1-xGdxFeO3 ceramics

BiFeO 3 has been recognized as one of the most important room-temperature single-phase multiferroic materials, but it still suffers from several drawbacks especially the weak magnetoelectric coupling. In the present work, the electric-field-controlled magnetism is achieved in Bi 1-x Gd x FeO 3 system, which involves a field-induced transition of Pna 2 1 / R 3 c at the morphotropic phase boundary region, and the magnetic state is switched between cycloidal state and canted antiferromagnetic state. The electric-field-controlled magnetism becomes reversible with the help of annealing, which is confirmed by magnetic hysteresis loops and the quantitative ratio of the involved phases for the as-sintered, as-poled and as-annealed samples. Compared with the systems of Bi 1-x Nd x FeO 3 and Bi 1-x Sm x FeO 3 , it is easier to tune the symmetry from R 3 c to Pna 2 1 with lower rare earth-content, and the field-induced transition is more apparent and subsequently leads to more significant electric-field-controlled magnetism in a wider composition range.