Magnetoelectric coupling in multiferroic BaTiO ₃ -CoFe ₂ O ₄ composite nanofibers via electrospinning

Abstract

Magnetoelectric (ME) coupling in Pb-based multiferroic composites has been widely investigated due to the excellent piezoelectric property of lead zirconate titanate (PZT). In this letter, we report a strategy to create a hybrid Pb-free ferroelectric and ferromagnetic material and detect its ME coupling at the nanoscale. Hybrid Pb-free multiferroic BaTiO3-CoFe2O4 (BTO-CFO) composite nanofibers (NFs) were generated by sol-gel electrospinning. The perovskite structure of BTO and the spinel structure of CFO nanograins were homogenously distributed in the composite NFs and verified by bright-field transmission electron microscopy observations along the perovskite [111] zone axis. Multiferroicity was confirmed by amplitude-voltage butterfly curves and magnetic hysteresis loops. ME coupling was observed in terms of a singularity on a dM/dT curve at the ferroelectric Curie temperature of BaTiO3. The lateral ME coefficient was investigated by the evolution of the piezoresponse under an external magnetic field of 1000 Oe and was estimated to be . These findings could enable the creation of nanoscale Pb-free multiferroic composite devices.