Dielectric, magnetic, and magnetoelectric properties of La and Ti codoped BiFeO3

The authors report on the dielectric, magnetic, and magnetoelectric (ME) properties of La and Ti codoped BiFeO3 (LBFTO). Codoping changes the structure of BiFeO3 from rhombohedral to tetragonal and the ferromagnetic properties of LBFTO are remarkably improved. More interestingly, the dielectric constant of LBFTO shows a linear increase with magnetic field and the slope decreases linearly with increasing temperature. The electric polarization of LBFTO also increases upon applying a magnetic field. The ME coupling coefficients of different orders were obtained by analyzing these data. The results were discussed by considering the doping induced destruction of the cycloidal structure in LBFTO. (C) 2010 American Institute of Physics. [doi:10.1063/1.3524225]