R&D: Thermal Microstructural and Magnetic Properties of Manganese Substitution Cobalt Ferrite Prepared via co-Precipitation Method

Journal of Materials Science: Materials in Electronics has published an article written by Ali A. Ati, Alyaa H. Abdalsalam, Nanotechnology and Advanced Materials Research Center, University of Technology (UOT), Al Sina’a Street, Baghdad, 10066, Iraq, and Ali S. Hasan, Department of Polymer and Petrochemical Industries, College of Materials Engineering, University of Babylon, Babylon, Iraq.

Abstract: “Manganese-substituted cobalt nano-ferrites, Co_(1−x)Mn_(x)Fe₂O₄ (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were synthesized using chemical co-precipitation method. Physical properties of Co_(1−x)Mn_(x)Fe₂O₄ nano-ferrites were then characterized using thermal gravimetric—differential thermal analysis (TGA/DTA), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectrometer, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). TGA/DTA study indicates that the thermal stability of the prepared manganese doped cobalt ferrite nanoparticles. X-ray diffraction patterns of all the prepared ferrite samples show good in quality, pure nanosized, single-phased cubical spinel structures, with ferromagnetic behavior. We demonstrated that the expansion of lattice constant (a) and crystallite size (D) induced by manganese substituted of cobalt ferrites exerted remarkable effects on its structural and magnetic properties. The lattice constant (a) and crystallite size (D) increase with increasing manganese substituted cobalt ferrites. Williamson–Hall (W–H) method was used to evaluate the crystallite size and lattice strain of the Co_(1−x) Mn_(x)Fe₂O₄ nanoparticles samples by peak broadening. The calculated crystal size of Co_(1−x) Mn_(x)Fe₂O₄ nanoparticles on the W–H plots were highly intercorrelated with the HR-TEM and results of Scherrer Deby equation. The other physical parameters, such as X-ray density, hopping length, ionic radius, bond length, tetrahedral edge, octahedral edge, and unshared octahedral edge values were estimated from the highest intensity peak (311) of X-ray diffraction. The Fourier transform infrared (FT-IR) spectrometer of the Co–Mn ferrite nanoparticles systems were recorded in the frequency range of 200–1000 cm⁻¹. FT-IR spectra show the two fundamental absorption bands of interstitial sub-lattice sites (M–O). The high absorption band (ν₁) and the low absorption band (ν₂) corresponds to the tetrahedral [A] and octahedral (B) sites, respectively, confirming the formation of single cubic spinel ferrite lattice system. The TEM results show that the ferrite nanoparticles have a nearly spherical shape with some agglomerations. From the analysis of VSM, the values of saturation magnetization (M_s) increases from 31.46 to 37.16 emu/g, then decreases with increasing Mn²⁺ ions substitution in the Co-ferrite system. The coercivity of the Mn²⁺ ions substituted cobalt ferrites increases up to x = 0.6 followed by a decrease. The optimized magnetic parameters suggest that the material with composition Co_0.6Mn_0.4Fe₂O₄ may be suitable for longitudinal magnetic recording media and other various technological applications.“