Enhancement in magnetoelectric properties of lead-free multiferroic composite through high-energy mechanical milling

Ferrite-Ferroelectric composites with the generic formula y (Mn 0.5 Cu 0.5 Fe 2 O 4 )1 − y [Ca 0.1 Ba 0.9 Zr 0.1 Ti 0.9 ] ( y = 25%, 50% and 75%) are prepared by solid-state reaction. One of the prepared samples of the composites 25%Mn 0.5 Cu 0.5 Fe 2 O 4 –75%Ca 0.1 Ba 0.9 Zr 0.1 Ti 0.9 O 3 (MCF-CBZT) is subjected to high-energy mechanical milling for different durations (12 h, 18 h and 30 h). The compositional stoichiometry of all the samples is checked by Energy Dispersive Spectroscopy. All the un-milled and milled samples are characterized by X-ray diffraction, scanning electron microscopy, FTIR, magnetometry, and dielectric and magnetoelectric coefficient measurements. Magnetoelectric composite possesses biphasic surrounding to exhibit complex behavior of ME effect. The present study reveals influence of mechanical milling on MCF-CBZT magnetoelectric composite. The XRD confirms the presence of ferrite and ferroelectric phases for all the samples and microstructural changes appear in SEM images of milled specimens. FTIR spectra show four characteristic bands in 400–800 cm −1 range. Saturation magnetization and Curie temperature decrease as milling duration increases. Relaxed broad doublet with the distribution of nuclear hyperfine fields is found in Mossbauer spectra indicating good coupling between ferrite-ferroelectric phases caused by mechanical milling for the multiferroic composite. The frequency response of dielectric constant and loss tangent is recorded in the frequency range from 100 Hz to 1 MHz. The static value of magnetoelectric factor has been studied as a function of magnetic field for un-milled and milled MCF-CBZT samples. The maximum value 382 μV/cm·Oe of (ME) H is observed for the 18 h milled MCF-CBZT sample.