Title screen

[References: 81 tit.]

Lead-free multiferroic 3-0 type particulate composites with a composition (1−x)(Ba0.85Ca0.15Zr0.1Ti0.9O3) - x(Ni0.7Zn0.3Fe2O4) [(1−x)BCZT - xNZFO with 0 ≤ x ≤ 100 at%] were prepared using solid state reaction method. Structural and microstructural analysis using XRD, FESEM and Raman techniques confirmed the phase formation of the ferroelectric (BCZT) and magnetostrictive (NZFO) phases without any detectable presence of impurity phases. Rietveld refinement of the XRD data revealed a tetragonal (P4mm) and a cubic structure (Fd3‾m) for the BCZT and NZFO phases, respectively. Elemental compositions of the constituent phases were assessed by EDS and XPS analyses. Electrical, magnetic, and magnetoelectric (ME) measurements were performed. The composites exhibit typical well-saturated magnetic hysteresis (M−H) loops at room temperature, having very low coercive field (HC) values, indicating their soft ferromagnetic behavior. Various parameters extracted from the M−H curves including HC, magneto-crystalline anisotropy, squareness, and magnetization were found to depend on x. Frequency dependence of capacitance and admittance exhibited a resonance behavior corresponding to the radial mode of the electromechanical resonance (EMR). ME coefficients were studied in both longitudinal (αE33) and transverse (αE31) modes. The highest coupling coefficients, αE31 ∼14.5 mV/Oe.cm and αE33 ∼13 mV/Oe.cm were obtained for composite with 50 at% NZF at off-resonance frequency of 1 kHz. At the EMR frequency of 314 kHz, the αE31 value in 0.5BCZT-0.5NZFO composite enhanced enormously to ∼5.5 V/Oe.cm. The studies conclude that x = 0.5 is an optimum atomic fraction of NZFO in the particulate composite for maximum ME coupling.