Magneto Optical Properties of FeBxFe2−xO4 Nanoparticles

Abstract

In this study, FeB x Fe 2-x O 4 nanoparticles (NPs) were synthesized by the polyol method. The M-H hysteresis curves exhibit superparamagnetic characteristics that are both coercivity and remanent magnetization values are negligible. The particle size dependent Langevin function was applied to calculate the magnetic particle dimensions around 9 nm. The measured magnetic moments of NPs are in range of (1.52-2.2) l B and almost half or less with respect to 4 l B of bulk Fe ferrite. Magnetic anisotropy was specified as uniaxial and calculated effective anisotropy constants (K eff ) are between 43.3 9 10 4 and 19.4 9 10 4 emu/g. The UV-Vis diffuse reflectance spectroscopy and Kubelka-Munk theory were used to determine the optical properties. The estimated optical band gap values (2.15-2.48 eV) of FeB x Fe 2-x O 4 NPs are bigger with respect to reported values (1.88-2.12 eV) for Fe 3 O 4 NPs in the literature. The bigger E g values are mainly attributed to B concentration and partly to quantum confinement effect.

Biocompatible Iron–Boron Nanoparticles Designed for Neutron Capture Therapy Guided by Magnetic Resonance Imaging

“…The magnetism of Fe–B NPs was quantitatively assessed by vibrating sample magnetometry (VSM) at room temperature, resulting in a superparamagnetic hysteresis loop (Figure 3B) consistent with a magnetic moment of 8241.8 ± 4.4 μ B per NP and a saturation magnetization of 70 emu per g‐Fe. The saturation magnetization is in agreement with that expected for Fe–B NPs, [ 69–71 ] where the magnetic ordering of Fe is weakened by spin canting states at grain interfaces and iron oxidation at particles surface, [ 72 ] as well as by dilution with a nonmagnetic element like B. [ 71,73 ]…”

“…The saturation magnetization is in agreement with that expected for Fe–B NPs, [ 69–71 ] where the magnetic ordering of Fe is weakened by spin canting states at grain interfaces and iron oxidation at particles surface, [ 72 ] as well as by dilution with a nonmagnetic element like B. [ 71,73 ]…”

Preparation and characterization of SPION functionalized via caffeic acid

“…Remnant magnetization and coercive field values of s-H curve have negligible magnitudes. The observed characteristic features of the spectra prove the superparamagnetic nature of NPs [32][33][34]. Fig.…”

Electromagnetic Properties and Humidity-Sensing Studies of Magnetically Recoverable LaMg x Fe1−x O 3−δ Perovskites Nano-photocatalysts by Sol-Gel Route

“…From the VSM measurements, saturation magnetization (M s ), remanent magnetization (M r ), and coercivity (H c ) values are evaluated and reported in Table 3. LaMg x Fe 1−x O 3−δ nanocrystalline shows a considerable saturation magnetization (M s ) at room temperature and the M s values decreased with the increase Mg content [14][15][16][17]. It may be because the magnetic nature of Fe 3+ (5 μB) ions was replaced by the nonmagnetic nature of [43].…”

“…The substitution of nonmagnetic Mg 2+ ion in LaFeO 3−δ changes their physicochemical and magnetic properties. The magnetic properties of ferrites are affected by composition as well as the type of substitution, cation distribution, and method of preparation [14][15][16][17].…”