Enhanced magnetoelectric coupling in transition-metal-doped BiFeO3 thin films

The transition-metal (TM) doped BiFeO3 thin films have been deposited on Si (100) substrate by spray pyrolysis technique and their electric, magnetic, ferroelectric and magnetoelectric properties were studied. The leakage current in Mn- and Co-doped BiFeO3 have been found to be about one order magnitude lower than that of BiFeO3 sample. The improvement in magnetization (Ms) and polarization (Pr) have been found in the TM doped BiFeO3 samples and reaching a maximum value of Ms~0.21 μB per formula unit for the Cr-doped and Pr~55.6 μC/cm2 for Mn-doped samples. The study of magnetoelectric coupling characteristics gave optimum coupling coefficient at critical value of the magnetic field, which may be due to the suppression of cycloid spin structure. The maximum coupling sensitivity of 10.48 V/cm Oe was observed for Mn doped samples.