Magnetic properties, critical behaviors and magnetocaloric effect in non-stoichiometric spinel type Co1+xCrxFe2-xO4

The magnetic properties, magnetocaloric effect, and critical analysis of magnetic behavior of Co1+xCrxFe2-xO4 (x = 0.125, 0.250, 0.375, and 0.500) with a non-stoichiometric ratio are studied in detail. All the synthesized samples exhibit single-domain behavior. The Cr3+ associated with excess Co2+ led to tuning the magnetic moment, exchange interaction, magnetocrystalline anisotropy constant, and microwave frequency. The second-order magnetic phase transition has been confirmed from the Arrot and Arrot-Noakes plots for all the samples. The Cr3+ associated with excess Co2+ also tuned the magnetocaloric (MCE) properties showing the maximum relative cooling power of 156 J kg-1, which is a higher value than that of previously reported Cr3+ substituted stoichiometric cobalt ferrite. The reliability of MCE and the nature of the magnetic phase transition of the investigated samples are confirmed by analyzing the critical exponent analysis, universal curve scaling, and scaling analysis of MCE.