The Structural and Magnetic Properties of Gadolinium Doped CoFe₂O₄ Nanoferrites

Abstract

Gadolinium substituted cobalt ferrite CoGd x Fe 2−x O 4 (x = 0, 0.04, 0.08) powders have been prepared by a sol-gel autocombustion method. XRD results indicate the production of a single cubic phase of ferrites. The lattice parameter increases and the average crystallite size decreases with the substitution of Gd 3+ ions. SEM shows that the ferrite powers are nanoparticles. Room temperature Mössbauer spectra of CoGd x Fe 22−x O 4 are two normal Zeeman-split sextets, which display ferrimagnetic behavior. The saturation magnetization decreases and the coercivity increases by the Gd 3+ ions.

Synthesis of single-phase cobalt ferrite nanoparticles via a novel EDTA/EG precursor-based route and their magnetic properties

“…In the present case average M s (69 emu/g) and H c (750 Oe) values of the synthesized Cobalt ferrite nanopowder were found to be lower than the theoretical values of M s (80 emu/g) and H c (5000 Oe) for the single crystal of cobalt ferrite [29]. The saturation magnetization at room temperature decreases as the crystalline size D decreases.…”

Magnetic and Mössbauer Spectroscopy Studies of Zinc-Substituted Cobalt Ferrites Prepared by the Sol-Gel Method

“…The Zn 2+ of the 3d 10 electron configuration has a zero angular momentum (l = 0), and it does not contribute to magneto-crystalline anisotropy. From our earlier research [32], the average particle size of CoFe 2 O 4 ( x = 0) is between 85.3 and 102.4 nm, and with increasing Zn content the particle size increases [23,33,34]. The sample’s magneto-crystalline anisotropy decreases with increasing Zn 2+ ions substituted for Co 2+ ions, with subsequent decreases in the coercivity [35,36].…”

Magnetic and structural properties of single-phase Gd3+-substituted Co–Mg ferrite nanoparticles

“…Indeed, by comparing our results with those found in the literature, we noticed that we observed similar structural behavior with that described in previous work, in terms of an increase in the lattice parameter and decrease in the average crystallite size, but totally different magnetic behavior. [21][22][23][24] Indeed, in the case of the two substitutions by magnesium and gadolinium, the saturation magnetization and coercivity decrease, whereas in our case the saturation magnetization and coercivity increase drastically despite having been doped with a low concentration of gadolinium. This phenomenon will be better elucidated later when discussing the magnetic properties.…”