Electric-field effects on magnetism of Fe/NCZF/PZT composite thin film

Electric field control of magnetism has many potential applications in magnetic memory storage, sensors and spintronics. Epitaxial heterostructure involving ferroelectric (FE), ferromagnetic (FM) materials is one of the possible routes towards the realization of devices exploiting sizable magnetoelectric effects. In this study, we prepared multiferroic composite ferromagnet/ferrite/ferroelectric thin films on SrTiO3(1 1 1) substrate by electron beam evaporation and pulsed laser deposition. This system represents a prototypical example of interface between body-centered-cubic Fe, spinel NCZF (Ni0.25Cu0.05Zn0.7Fe1.96O3.96) and perovskite PZT (PbZr0.52Ti0.48O3), respectively. Magnetoelectric effects measured as a function of bias voltage on these heterostructures have been investigated via magneto-optical Kerr effect (MOKE). The magnetic coercivity (Hc) considerably decreased as a voltage was applied. The Hc values exhibited the similar variation whether the applied voltage was positive or negative and the reversibility was demonstrated. The strain coupling-mediated magnetoelectric effect and local heating effect are supposed to be the possible origins of Hc variation.