Dielectric, ferroelectric and magnetic properties of Pb0.95Pr0.05Zr0.52Ti0.48O3 – CoPr0.1Fe1.9O4 ceramic composite

Abstract

We investigate the structural, dielectric, ferroelectric and magnetic properties of a ferroelectric-ferrite material: praseodymium doped lead zirconium titanate (PZT) and cobalt ferrite (CFO) composite. The praseodymium doped PZT and CFO powders were synthesized separately by sol-gel auto combustion technique. The ferroelectric-ferrite composites were then synthesized by mixing the appropriate amount of individual phases using conventional sintering method. The morphological studies revealed a uniform distribution of grains of parent phases in the composite. Powder X-ray diffraction studies showed that the Pr doped PZT possess tetragonal perovskite structure while as Pr doped CFO possesses cubic spinel structure. The parent phases retain their crystal structures in the composite, without formation of any new secondary phase. The dielectric studies of composite, in the temperature range 100–750 K at a selected frequency of 100 kHz, revealed a diffused ferroelectric phase transition. Variation of dielectric constant with frequency in the range of 20 Hz- 3 MHz was carried out at room temperature. The reduction in the leakage current due to Pr doping leads to typical saturated P-E hysteresis loops for the composite, confirming their ferroelectric nature. The low temperature ac conductivity follows Motts law, confirming the hopping conduction mechanism in the composites. At room temperature, the composite exhibit typical magnetic hysteresis loop, indicating the presence of a long range magnetic order. The calculated values of squareness ratio for the composites confirmed the presence of multi-domain structure.