Doping assisted structural transition in copper substituted MgFe2O4 ferrite: Thermal, electrical andmagnetic properties

A cubic to tetragonal structure transition has evolved by substitution of Cu2+ ions in magnesium ferrite, fabricated via the sol-gel method. TEM studies revealed quasi-spherical particles for MgFe2O4 and rod-shaped particles for CuFe2O4, suggesting an enhancement of morphological anisotropy with Cu doping. Thermal analysis shows the formation of MgFe2O4 and CuFe2O4 at 380C and 340C, respectively, indicating a reduction in temperature for the formation of samples with copper doping. XRD shows the structural transition from a cubic to a tetragonal structure with increasing copper concentration. The dc electrical resistivity decreases with copper doping in MgFe2O4, attributing to the increase in conductivity due to Cu2+-Cu+ ions hopping. MgFe2O4 has been found to have a saturation magnetization of 23 emu/g and a coercive eld of 54 Oe. The saturation magnetization increases, while coercivity initially decreases and then increases with increasing copper concentration.