Structural, magnetic, dielectric, magneto-electric and ferroelectric properties of BaTiO3-NiFe2O4 multiferroics

Multiferroics having composition yNiFe2O4 -(1-y) BaTiO3(y = 0.10, 0.30 and 0.50) have been prepared through the solid-state reaction route. These samples constitute NiFe2O4 as the ferromagnetic phase and BaTiO3as the ferroelectric phase. The X-ray diffraction (XRD) has been carried out to investigate the crystal structure for-mation and phase purity of the prepared ceramic samples. Rietveld refinement of XRD patterns confirm the presence of cubic (Fd3m) and tetragonal (P4mm) symmetries in all the samples. The effect of ferrite (NFO) concentration on magnetic, dielectric, ME coefficient and ferroelectric properties of samples has been studied further. The recorded M-H loops at room temperature, reflects the ferromagnetic nature of all samples. These hysteresis loops are fitted by LAS (law of approach to saturation), and the values of various magnetic parameters are evaluated. A gradual enhancement in magnetic parameters is noticed with an increased in NFO concentra-tion. Variations of dielectric constant (& epsilon;') and loss tangent (tan & delta;) as a function of frequency as well as of temperature at various selected frequencies (10 kHz, 100 kHz, 500 kHz, and 1 MHz) have been studied. The highest value of magnetoelectric (ME) response has been observed for thesample0.10NiFe2O4-0.90BaTiO3. P-E loops show an enhancement in both the coercive field and the remnant polarization with an increment in ferrite content at room temperature.