Field-dependent magnetization of BiFeO3 in an ultrathin La0.7Sr0.3MnO3/BiFeO3 superlattice

Abstract

We report the observation of field-dependent magnetization of BiFeO3 (BFO) in an ultrathin BFO/La0.7Sr0.3MnO3 (LSMO) superlattice using polarized neutron reflectivity (PNR). Our PNR results indicate parallel alignment of magnetization across BFO/LSMO interfaces. The study showed an increase in average magnetization of the BFO layer on increasing applied magnetic field at 10 K, similar to the ferromagnetic nature of LSMO. We obtained a saturation magnetization of 110 +/- 15 kA/m (similar to 0.8 mu(B)/Fe) for an ultrathin BFO layer (similar to 2 unit cells) sandwiched between ultrathin LSMO layers (similar to 2 unit cells), which is much higher than the canted moment (0.03 mu(B)/Fe) in the bulk BFO.