Magnetic and electric properties of BFO–NFO nanocomposites

Multiferroic nanocomposites of (1?x)BiFeO₃–xNiFe₂O₄ for x=0.2, 0.4, and 0.6 were prepared by a sol gel technique. The synthesized nanocomposites were characterized by X-ray diffraction (XRD). XRD confirmed, they being nanocomposites having desired phase with crystallite size ranging from 14.0 nm to 3.6 nm. The morphological analysis was done with the help of Transmission electron microscopy (TEM), which revealed the particle size to be in the range of 10–7 nm. Polarization–electric field (P–E) loop tracer was used to determine the ferroelectric properties of the nanocomposites. The dielectric constant at room temperature was analyzed upto 1 MHz frequency and was found to increase with increasing concentration. In order to investigate the magnetic behavior, a superconducting quantum interference device (SQUID) was used. The nanocomposites were analyzed by increasing the magnetic field up to 25 kOe and the magnetization was found to increase from 6 emu/g for x=0.2–10 emu/g for x=0.6, which was found to be optimum for the technological applications. The appropriate combination of two phases gave rise to higher magnetization.