Structural, electric, magnetic, and magneto-dielectric properties of (1−x) Ba0.95Yb0.05TiO3-(x) NiFe1.95 Yb0.05O4 multiferroic composites

We have investigated the structural, dielectric, ferroelectric, magnetic, and magneto-dielectric properties of (1 − x) Ba_0.95Yb_0.05TiO₃-(x) NiFe_1.95Yb_0.05O₄ (where x = 0.02, 0.05, 0.07, 0.1) multiferroic composites. The Yb-doped BaTiO₃ and NiFe₂O₄ powders were synthesized separately by auto combustion technique. The multiferroic composites were then synthesized using conventional sintering method. X-ray diffraction studies showed that parent phases retain their crystal structures in the composites without formation of any new secondary phases. Dielectric study of the multiferroic composites, in the temperature range 100–400 K revealed two ferroelectric phase transitions. The increase in dielectric constant and reduction in leakage current due to Yb doping leads to typical ferroelectric hysteresis loop. At room temperature, the composites exhibit typical magnetic hysteresis loop, indicating the presence of long range magnetic order. Magnetodielectric results reveal that the magnetic ordering of the NiFe_1.95Yb_0.05O₄ phase leads to an increase in the number of polar domains of the Ba_0.95TiYb_0.05O₃ phase, which in turn leads to an improvement in the magnetodielectric effect. The overall findings of this research work established the unification of Ba_0.95TiYb_0.05O₃ and NiFe_1.95Yb_0.05O₄ phases in multiferroic composites and their coupling has been strengthened, which positions these materials as possible candidates for use in multifunctional devices.