Structural elucidation and magnetic behavior evaluation of rare earth (La, Nd, Gd, Tb, Dy) doped BaCoNi-X hexagonal nano-sized ferrites

• Published in: Journal of magnetism and magnetic materials 2016-06, Vol.408, p.147-151
• Main Authors: Majeed, Abdul, Khan, Muhammad Azhar, Raheem, Faseeh ur, Hussain, Altaf, Iqbal, F., Murtaza, Ghulam, Akhtar, Majid Niaz, Shakir, Imran, Warsi, Muhammad Farooq
• Format: Article
• Language: English
• Subjects: Cations; Coercive force; Coercivity; Ferrites; Fourier transforms; FTIR; Infrared spectroscopy; Nanoferrites; Nanomaterials; Nanostructure; Rare earth metals; Saturation magnetization; XRD
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2016.02.061

Rare-earth (RE=La3+, Nd3+, Gd3+, Tb3+, Dy3+) doped Ba2NiCoRExFe28−xO46 (x=0.25) hexagonal ferrites were synthesized for the first time via micro-emulsion route, which is a fast chemistry route for obtaining nano-sized ferrite powders. These nanomaterials were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), as well as vibrating sample magnetometer (VSM). The XRD analysis exhibited that all the samples crystallized into single X-type hexagonal phase. The crystalline size calculated by Scherrer's formula was found in the range 7–19nm. The variations in lattice parameters elucidated the incorporation of rare-earth cations in these nanomaterials. FTIR absorption spectra of these X-type ferrites were investigated in the wave number range 500–2400cm−1. Each spectrum exhibited absorption bands in the low wave number range, thereby confirming the X-type hexagonal structure. The enhancement in the coercivity was observed with the doping of rare-earth cations. The saturation magnetization was lowered owing to the redistribution of rare-earth cations on the octahedral site (3bVI). The higher values of coercivity (664–926Oe) of these nanomaterials suggest their use in longitudinal recording media. Nano-sized rare-earth (RE=La3+, Nd3+, Gd3+, Tb3+, Dy3+) doped Ba2NiCoRExFe28−xO46 (x=0.25) hexagonal ferrites were synthesized for the first time via micro-emulsion route and the crystallite size was found in the range 7–19nm. The enhancement in the coercivity was observed with the doping of rare-earth cations. The higher values of coercivity (664–926Oe) of these nanomaterials suggest their use in longitudinal recording media. [Display omitted] •Micro-emulsion route was used to synthesize Ba2NiCoRExFe28−xO46 ferrites.•The crystallite size was found in the range 7–19nm.•The rare-earth incorporation enhanced the coercivity (664–926Oe).•The optimization of coercivity suggests their use in longitudinal recording media.