Fe²⁺ Contents and Magnetocrystalline Anisotropy in Iron Defect LiZnTiMn Ferrites

Abstract

An investigation of the effects of the iron defect k in LiZnTiMn ferrites using Mössbauer spectroscopy and ferromagnetic resonance techniques was carried out in single-phased samples. Results show that the isomer shifts have values corresponding to a compound with either low-spin Fe(II), low-spin Fe(III), or high-spin Fe(III). On the other hand, the Lande factor and the ferromagnetic resonance linewidth disclosed that g is always very close to 2, being equal to 2.02 when k = 0.06. A minimum in ΔH was detected for this value of k. From these results, the possible presence of Fe2+ in the samples could be excluded, and it was concluded that the changes in ΔH are due to the variation of the Fe(III) contents in the tetrahedral and octahedral sites. The existence of the minimum in ΔH is due to a compensation point in the magnetocrystalline anisotropy.

Investigating the role of diamagnetic Cd2+ ions on the structural, optical, and magnetic properties of YIG

“…The isomer shift value is between 0.168 and 0.510 mm s −1 for T=77 K and between 0.362 and 0.382 mm s −1 for T=300 K and the quadrupole splitting value is between 0.01 and 0.17 mm s −1 for T=77 K and between 0.04 and 0.30 mm s −1 for T=300 K corresponding to octahedral and tetrahedral sites. These results indicate the existence of Fe 3+ in both sites and the absence of Fe 2+ and Fe 4+ [37,38]. Therefore, no distortion was caused by the substitution of Y 3+ by Cd 2+ .…”

The rapid response and high sensitivity of a ruthenium-doped copper ferrite thin film (Ru–CuFe2O4) sensor

“…Ruthenium could substitute for iron in iron sites, with interactions between these ions leading to iron defects. 13,14 The iron defects can be termed as Fe 2 O 3 secondary phases, which have been shown to increase surface-to-volume ratios. Increasing surface area has been shown to directly lead to increased impacts on sensing.…”