Impact of La on Structural, Morphological and Magnetic Properties of NiCoFe 2O4 Nano Ferrites

Abstract

Ni0.₂Co_0.8Fe_2-xLa_xO₄ (x = 0.02, 0.06, 0.10) nano ferrites have been synthesized by Sol-gel auto combustion method using urea as a fuel. The sample calcinations have been performed at 800^oC for 4 hours. The synthesized samples were subjected to study X-ray diffraction spectroscopy (XRD) for structural investigations. All the samples were found to constitute Face Centered Cubic (FCC) spinel structure belonging to the Fd3m space group. The XRD results show the single cubical phase formation in the heated samples. Energydispersive X-ray spectra confirmed the presence of Ni, Co, La Fe and O elements with no existence of any impurity. The average crystallite size was decreased by varying the concentration of La from 10 to 8 nm. The Field Emission Gun Scanning Electron microscopy (FEG-SEM) and Field Emission Gun transmission electron microscopy (FEGTEM) have given the morphological study of the samples. It is also found that the value of the lattice constant decreases with increases in La concentration. The magnetic properties of the samples were investigated by using a vibrating sample magnetometer (VSM). The results obtained from VSM show that the value of both magnetization (Ms) and coercivity (Hc) decreases with an increase in diamagnetic La concentration.

Keywords: Spinel ferrites, Sol-gel, SEM, TEM, VSM.