Low temperature magnetic study and first principle calculation in ‘Mo’ doped CoFe2O4 for magnetic information storage applications

Abstract

Structural and low temperature magnetic properties of CoFe2−xMoxO4 (x = 0.01, 0.03 and 0.05) were studied in the present work. Rietveld refinement of XRD patterns of CoFe2−xMoxO4 (x = 0.01, 0.03 and 0.05) confirm the pure phase cubic crystal structure in Fd3m space group. The decrease in lattice parameters (a contraction of the lattice) has been observed with doping, which confirms the probability of substitution of ‘Mo’ at the octahedral site of parental CoFe2O4 (CFO). The micro-strain via W-H plots was found to be enhanced for CoFe1.95Mo0.05O4 (CMFO5) sample which confirms the incorporation of ‘Mo’ atoms at Fe-site and subsequently reducing impurities as observed from refined patterns. The low temperature (2K) magnetic parameters were found to be greatly enhanced with ‘Mo’ substitution. We observed the decrease in anisotropy constant of Co2+ ions with ‘Mo’ doping and Mo6+ ions concentration at the tetrahedral site of CFO, increases the magnetization of the samples. Both M-H and ZFC-FC measurements confirm the ferrimagnetic behavior of all the samples. The maximum value of information storage parameter ‘S’ achieved around 0.442 for x = 0.03 sample at 2K. The structural parameters, electronic (density of states and band structure) and magnetic properties of pure CFO have also been investigated via computational first principle based density functional theory (DFT) calculations. The computational results are in good agreement with the experimental outputs.