Qualitative Description of Magnetoelectric Coupling in Multiferroic BTO/CFO Janus Fibers

The magnetoelectric coupling dynamics in multi-phase multiferroic materials was investigated in a perovskite-spinel fiber system with Janus structure consisting of ferroelectric barium titanate (BTO) and ferrimagnetic cobalt ferrite (CFO). We observed strong evidence of such coupling from the distinct changes in the second harmonic generation signals under different applied magnetic field orientations. Here, we provide a clear qualitative description of how the electrical polarization of the BTO half is affected by the changes incurred in the magnetization of the CFO half in different groups of fibers. We observed that although the results vary for different fiber ensembles due to the memory of the initial system, the subsequent changes in the fiber system correlate qualitatively and can be understood in a systematic way with our simple dipole model.