Structural transformation and magnetoelectric behaviour in Bi_1−<i>x</i>Gd_<i>x</i>FeO₃multiferroics

The crystal structure, dielectric, magnetic and magnetoelectric (ME) properties of Bi1-xGdxFeO3 (BGFO, x = 0, 0.05, 0.1, 0.15, 0.2) multiferroic ceramics have been studied. The substitution of bismuth by gadolinium induces a R3c -> Pnma phase structural transition at x > 0.1, which leads to the suppression of the spiral modulated spin structure and develops weak ferromagnetic properties in the BiFeO3-based materials. Through studying the temperature/magnetic field dependence of the ME coefficient, we have revealed the effect of the substitution of Gd3+ ions on the ME properties, and have demonstrated the possibility of manipulating the electric state in BGFO multiferroics by applying magnetic field at room temperature.