Tuning of magnetic property by lattice strain in lead substituted cobalt ferrite

Co1−xPbxFe2O4 (x = 00-0.15) have been synthesized using citric acid modified sol-gel method. Samples for x ≤ 0.02 have been ball milled to reduce the particle size. Hence, all the materials under the study are in almost equal crystallite size (∼15 nm). The phase purity and structural study have been carried out using X-ray powder diffraction (XRD) technique. The Rietveld refinement of XRD patterns reveals the increasing lattice parameter with the lead (Pb) concentration. Detailed analysis of the Raman spectroscopy data supports the XRD pattern analysis results. Magnetic hysteresis loop measurements have been performed using Vibrating Sample Magnetometer (VSM) at room temperature over field range of ±20 kOe. Magnetocrystalline anisotropy constant was calculated using Law of Approach (LA) to saturation, which shows increasing behavior till 2% Pb concentration. The large difference in experimental and theoretical saturation magnetic moment per formula unit shows existence of three sublattice model suggested by Yafet-Kittel.