Multiferroic and magnetoelectric studies on BMFO–NZFO nanocomposites
Bismuth ferrite-based multiferroic composites, x⋅Bi0.95Mn0.05FeO3 − (1 − x)⋅Ni0.5Zn0.5Fe2O4, where x takes the values of 0.2, 0.4, 0.5, 0.6 and 0.8, have been prepared by combining sol–gel autocombustion and solid-state methods. Phase identification of the samples was done by X-ray diffraction analysis. SEM–EDX measurements on the samples were used to evaluate the microstructural aspects and quantitative evaluation of the samples. Room temperature P–E loop measurements on the samples were done under the application of external electric fields in the range from 0 to 6 kV/mm at a frequency of 50 Hz to understand the ferroelectric strength of the compounds. Magnetic studies on the samples were made by M–H loop measurements in the field range of ± 10 kOe. Magnetoelectric coupling measurements were made using a dynamic lock-in test set-up. The results indicate that the mixing of nickel–zinc ferrite in Bi0.95Mn0.05FeO3, in spite of the enhanced conductivity, has produced considerable improvements in saturation magnetization while retaining the remnant ferroelectric polarization in reasonable magnitudes to obtain improved M–E coupling. Among all the composites, the composite with x = 0.5 has resulted better M–E performance.
One of the authors (Pratap Kollu) thanks The Royal Society London for extending partial support during the course of investigations and UGC NRC, School of Physics, University of Hyderabad, India.