Temperature dependent structural and magnetic properties of Cerium substituted Co–Cr ferrite prepared by auto-combustion method

The effects of heat treatment on a nano-crystalline spinel ferrite with chemical formula CoCr_0.04Ce_xF_e1.96−xO₄ (x=0.06) were investigated in the present work. The sample was prepared by the auto-combustion method and then heat treated at 700–1200 °C for 8 h. The sample heat treated at these temperatures was investigated using thermo-gravimetric analyses and differential scanning calorimetry, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and vibrating sample magnetometery. The XRD patterns and IR spectra confirmed that the synthesized materials were of single phase at and above 900 °C. The average particle size was found to be in the range of 30.8–63.8 nm estimated by the Scherer formula. IR studies confirm two main absorption bands in the frequency range of 400–800 cm⁻¹ arising due to the tetrahedral (A-site) and octahedral (B-site) stretching vibrations. The average grain size increased with the increase of temperature while distribution of particles became homogeneous as observed by scanning electron microscope. The saturation magnetization was increased gradually from 7.4 to 59.6 emu/g with the increase of temperature. The coercivity lies in the range of 248–811 Oe as a function of temperature. The obtained results suggest that the investigated materials may be potential candidates for high density recording media applications. - Highlights: • Effects of temperature on structural and magnetic parameters of spinel ferrite are studied. • The XRD patterns confirms that the materials are of single phase at and above 900 °C. • The M_s was increased gradually from 7.4–59.6 emu/g with the increase of temperature. • The values of coercivity lie in the range of 248–811 Oe as a function of temperature. • The results show that materials may have a potential for high density recording media