Structural and magnetic behaviour of sol-gel prepared Ni_0.5Co_0.5Gd_0.025Tb_0.025Dy0.025Ho_0.025Fe_1.99O₄ for energy harvesting applications

In this work the impact of multi rare earth (RE) doping (especially four RE elements as dopants at B-site in equi molar concentration) on properties of Ni0.5Co0.5Fe2O4 was discussed. Ni-Co spinel ferrite with four RE elements at B-site i.e. Ni0.5Co0.5Gd0.025Tb0.025Dy0.025Ho0.025Fe1.99O4 (NC-4R) was successfully synthesized by sol-gel process. From XRD and Raman data FCC spinel structure with Fd-3m space group was observed. Both experimental and theoretical data showed good agreement in Rietveld refinement. Five Raman modes with shoulder like peaks confirm the cubic and mixed spinel structure. Magnetization behaviour with magnetic field and temperature are discussed. NC-4R showed good strain sensitivity i.e. 0.5x10(-9) A(-1)m at lower magnetic field i.e. 1350 Oe which is helpful in energy harvesting applications.