Azimuthally Controlled Magnetic and Dielectric Properties of Multiferroic Nanocrystalline Composite by Magnetic Coupling and Charge Hopping

Abstract

Multiferroic composite is an environmentally friendly material with the extraordinary multisusceptible and high storage properties. It is significant to find an effective way for designing and fabricating high-quality materials. In this context, the BTO/NZFO nanocrystalline multiferroic composite thin films with and without (100) oriented spinel ferrite were prepared by RF magnetron sputtering. The saturation magnetization, coercivity, and initial susceptibility of composite thin films with (100) oriented spinel NZFO phase are 1.05, 1.75 to 2.08, and 1.15 times as high as those of the composites without orientation, respectively. The dc conductivity and dielectric loss of the composite thin film with (100) oriented NZFO are 18 and 33.3% lower than those of composite without orientation, respectively. It is exhibited that the magnetic and dielectric properties of the BTO/NZFO multiferroic composite thin films are azimuthally controlled by distribution of the Zn/Fe–O–Ni/Fe superexchange coupling and charge hopping between Fe2+–Fe3+ pair, respectively. Obviously, controlling the arrangement of magnetic couplings and charge hopping is an effective route to fabricate the multiferroic composite with the optimal or specific magnetic and dielectric properties.