Magneto-dielectric studies on multiferroic composites of Pr doped CoFe2O4 and Yb doped PbZrTiO3

Abstract

Multiferroic composites with remarkable magnetoelectric effect (ME) are unique candidates for multifunctional devices. This study focuses on the structural, dielectric, ferroelectric, magnetic and ME properties of ferromagnetic (Pr doped CoFe2O4) and ferroelectric (Yb doped PbZrTiO3) composites with the general formula x CoPr0.1Fe1.9O4- (1-x) Pb0.95Yb0.05Zr0.52Ti0.48O3 (x = 0.02, 0.05 and 0.1). The individual phases namely Pr doped CoFe2O4 (CFO) and Yb doped PbZrTiO3 (PZT) for the composites were synthesized by sol-gel auto combustion technique. The powder X-ray diffraction technique showed that the Yb doped PZT retains its tetragonal perovskite structure, while as Pr doped CFO possesses cubic spinel structure. The morphological studies showed a uniform distribution of grains of parent phases in the composites. The dielectric studies in the temperature range of 100–750 K at a selected frequency (100 kHz) revealed a diffused phase transition confirming a ferroelectric to paraelectric phase transition. The composites show well-saturated P-E loops. The room temperature magnetic studies exhibit saturated M-H loops, with dilution of magnetic parameters for the composite. A favorable decrease in magneto-crystalline anisotropy calculated by Law of Approach was observed with decreasing ferrite content in the composite. The magneto-dielectric studies at room temperature confirm a negative magnetoelectric coupling in the composite. The Landau free energy approach confirmed a bi-quadratic coupling in the composites.