Mössbauer Spectroscopy, Structural and Magnetic Studies of Zn²⁺Substituted Magnesium Ferrite Nanomaterials Prepared by Sol-Gel Method

Abstract

Zinc substituted magnesium ferrite nanomaterials Mg 1− Zn Fe 2 O 4 ( = 0, 0.1, 0.3, 0.5, 0.7) powders have been prepared by a solgel autocombustion method. The lattice parameter increases with increase in Zn concentration, but average crystallite size tends to decrease by increasing the zinc content. SEM results indicate the distribution of grains and morphology of the samples. Some particles are agglomerated due to the presence of magnetic interactions among particles. Room temperature Mössbauer spectra of Mg 1− Zn Fe 2 O 4 shows that the A Mössbauer absorption area decreases and the B Mössbauer absorption area increases with zinc concentration increasing. The change of the saturation magnetization can be explained with Néel's theory. It was confirmed that the transition from ferrimagnetic to superparamagnetic behaviour depends on increase in zinc concentration by Mössbauer spectra at room temperature. Saturation magnetization increases and coercivity decreases with Zn content increasing.

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

“…As a result, the decrease of coercivity is attributed to the reduction of the magnetic anisotropy. The anisotropy contribution comes from Co 2+ ions of the octahedral B site, due to the electron configuration of Co 2+ being 3d 7 [13], as well as the ion’s spin and incompletely frozen orbital angular momentum coupling [30,31]. 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.…”

Structural and Magnetic Property of Cr3+ Substituted Cobalt Ferrite Nanomaterials Prepared by the Sol-Gel Method

“…Therefore, the change of the magnetic hyperfine field can be explained as the average grain size caused by the change of the calcination temperature [8]. The absorption area of Mössbauer energy for CoCr 0.2 Fe 1.8 O 4 calcined at different temperatures exhibited certain changes, which indicated that the calcining temperature influenced the fraction of the Fe 3+ ions in the tetrahedral A and octahedral B sites [6,20,21].…”

Effects of Al3+ Substitution on Structural and Magnetic Behavior of CoFe2O4 Ferrite Nanomaterials

“…The anisotropy is attributed to Co 2+ ions in the octahedral site, causing frozen orbital angular momentum and spin coupling [22]. The Al 3+ ions elicit zero angular momentum (l = 0), which does not affect magnetic anisotropy [23,24,25]. When Al 3+ ions were replaced with Fe 3+ ions, the spin-orbit coupling weakened and magnetocrystalline anisotropy decreased.…”