Structure and magnetic properties of Co–Ni–Li ferrites synthesized by citrate precursor method

• Published in: Journal of magnetism and magnetic materials Vol. 324; no. 22; pp. 3846 - 3852
• Main Authors: Assar, S.T., Abosheiasha, H.F.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2012; Elsevier
• Subjects: Citrates; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Density; Exact sciences and technology; Ferrite; Magnetic properties; Magnetic properties and materials; Magnetic properties of nanostructures; Metal ions; Nanoparticle; Nanostructure; Physics; Precursors; Saturation magnetization; Spinel; Transmission electron microscopy; X-ray diffraction; X-ray diffraction; IR; Ferrite; Nanoparticle; Saturation magnetization; Cubic lattices; Particle size; Magnetization; Magnetic hysteresis; XRD; Ion distribution; Nanoparticles; Ferrites spinels; Transmission electron microscopy; Remanent magnetization; Coercive force; Chemical composition; Porosity; Fourier-transformed infrared spectrometry; Microstructure
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2012.06.033

Nanoparticles of Co0.5Ni0.5−2xLixFe2+xO4 with x ranging from 0.00 to 0.25 in steps of 0.05 were prepared by using citrate precursor method. The microstructure and the magnetic properties of the as-prepared nanosamples and the effect of increasing Li1+ ions on their physical properties were studied. X-ray diffraction (XRD), transmission electron microscopy (TEM), particle size analyzer (PSA), Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer (VSM) were used to investigate the samples. The XRD analysis confirmed the cubic spinel phase formation of the prepared samples, while TEM images and PSA ensure the nanostructural features of them. The FTIR spectra reveal the presence of two prominent absorption bands v1 and v2 in the range of 600 and 400cm−1 which are usually attributed to the tetrahedral and octahedral complexes of the spinel lattice, respectively. The change of v2 gradually towards lower frequency and the slightly change of v1 were explained depending on the effect of increasing Li1+ content on the bond length of B-site metal ions and the spin canting of A-site metal ions, respectively. Saturation magnetization and remnant magnetization were found to increase with adding Li1+ ions up to x=0.15 and then to decrease again, while coercivity decreases monotonically by increasing Li1+ ions. The change in magnetic properties by adding Li1+ ions is explained as to be dependent on many factors such as crystallite size, measured density, porosity, expected cation distribution, A–B exchange interactions, and magnetocrystalline anisotropy. ► Co0.5Ni0.5−2xLixFe2+xO4 (0.0≤x≤0.25 in steps of 0.05) were prepared by citrate precursor method. ► Structural, morphology and magnetic properties of the prepared samples were investigated. ► The effect of adding Li1+ ions in enhancing the magnetic properties of the samples were studied. ► All the result obtained from XRD data, FTIR spectra and VSM data reinforce each other. ► The PSA and TEM estimated data are in a good agreement and ensure the nanoscale of the particle sizes.