Exploring Study of Magnetic and Electrical Properties of Tl3+ Doped Co0.5Ni0.5Fe2O4 Spinel Ferrites

Abstract

Co_0.5Ni_0.5Fe_2-xTl_xO₄ (x=0, 0.05, 0.1, 0.15, and 0.2) spinel ferrites were prepared via the sol-gel technique. The XRD analysis revealed a single-phase spinel structure. The lattice constant ‘a’ increased from 8.223-8.269Å with doping of Tl⁺³ due to larger ionic radii of Tl⁺³ than Fe⁺³ ions. The mass susceptibility at 300K decreased from 7.46 x 10^-3-4.15 x 10^-3 cm³/g due tothe weakening of AB interactions followed by a decrease in Curie temperature from 453K to 408K. The electrical permittivity follows the Maxwell-Wagner model and Koop’s theory. The dc resistivity of ferrites at 300K increased from 1.82x10⁹-9.23x10⁹ ?-cm with increasing Tl⁺³ contents due to increased hopping lengths. The activation energy obtained from Arrhenius plots increased from 0.126 to 0.131eV, increasing Tl⁺³contents