Influence of La substitution on the structural and magnetic properties of CuCdCo spinel nanoferrite

Abstract

This study presents modifications of the structural and magnetic properties of Cu_0.5Cd_0.25Co_0.25La_xFe_2-xO₄ where x = 0.0, 0.02, 0.04, 0.06, 0.08, 0.1 nano-structured spinel ferrites through doping La³⁺ ions. The analyzed ferrites powder were produced via the sol–gel combustion process and characterized using X-ray Diffraction (XRD), High Resolution Transmission Electron Microscopy (HRTEM), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Analysis (EDAX), Fourier Transform Infrared Spectroscopy (FTIR), and Vibration Sample Magnetometer (VSM). The creation of a single-phase nanostructure in the produced material was verified by XRD analysis. The influence of La³⁺ ions on crystallite size, grain size, lattice constant, dislocation densities, bulk densities, porosity, and hoping lengths was assessed. XRD analysis confirms that all samples exhibit the formation of the cubic spinel structure with Fd3m space group. The crystallite size (23 nm-8 nm) and lattice dimension (8.4610 Å-8.3690 Å) showed a significant random nature corresponding to the doping Fe³⁺ (0.67 Å) by small La³⁺ (1.06 Å). The IR absorption spectra recorded in the 350–2500 cm⁻¹ range, with the tetrahedral complexes showing higher frequency band (ʋ₁) at 536–666 cm⁻¹ and the octahedral complexes generating the lower frequency band (ʋ₂) at 390–428 cm⁻¹, and they are the characteristic feature of spinel structure. The images obtained through FESEM and HRTEM reveal the existence of particles characterized by spherically cubic shaped crystallites. The measurement of the magnetic parameters was conducted through VSM. The observed M−H loop, with saturation magnetization (26.82 emu/g-41.61 emu/g), remanent magnetization (4.92 emu/g-14.00 emu/g), coercivity (190.68 Oe-857.24 Oe), and Magnetic Moment (1.2339–1.8895) show the soft magnetic pseudo-single domain structure. The initial incorporation of La³⁺ leads to an increase in Ms, Mr, Hc, and ƞ_Β followed by a subsequent decrease.