Evaluation of (BH)max and magnetic anisotropy of cobalt ferrite nanoparticles synthesized in gelatin

Abstract

Evaluation of (BH)max and magnetic anisotropy of cobalt ferrite nanoparticles synthesized in gelatin, Ceramics International, http://dx. AbstractCoFe 2 O 4 nanoparticles were synthesized using gelatin as a polymerizing agent. Structural, morphological and magnetic properties of samples treated at different temperatures were investigated by X-ray diffraction, scanning electron microscopy, Mössbauer spectroscopy and magnetization measurements. Our results revealed that the samples annealed at 623 K and temperatures above 973 K have a cation distributions given by (Co 0.19 Fe 0.81 )[Co 0.81 Fe 1.19 ]O 4 and (Co 0.06 Fe 0.94 )[Co 0.94 Fe 1.06 ]O 4 ,respectively. The particle sizes varied from 73 to 296 nm and the magnetocrystalline anisotropy, K 1 , has values ranging from 2.60x10 6 to 2.71x10 6 J/m 3 , as determined from the law of approach to saturation applied to the MxH data at high field. At 5 K, the saturation magnetization, coercive field and (BH) max varied from 76 to 95 Am 2 /kg, 479.9 to 278.5 kA/m and 9.7 to 20.9 kJ/m 3 , respectively. The reported values are in good agreement with near-stoichiometric cobalt ferrite samples.

Influence of Dy3+Ions on the Microstructures and Magnetic, Electrical, and Microwave Properties of [Ni0.4Cu0.2Zn0.4](Fe2–xDyx)O4(0.00 ≤x≤ 0.04) Spinel Ferrites

“…The values of A inhomogeneity parameter and χ susceptibility are negligible A → 0 and χ → 0 in high magnetic fields H → ∞. 60 The A 2 anisotropy parameter for the cubic structure may be written as 61 where K eff is the effective magnetic crystal anisotropy coefficient. The 8/105 numerical coefficient holds for random polycrystalline samples with cubic anisotropy.…”

Effects of postdeposition heat treatment on the structural and magnetic properties of CoFe2O4 nanoparticles produced by pulsed laser deposition

“…One doublet was assigned to high-spin Fe 3þ located in the tetrahedral site A and the other to high-spin Fe 3þ in the octahedral site B of the CoFe 2 O 4 . 31,32 From the ratio f A /f B between the absorption area of the doublets, we can obtain the relative fraction of Co in tetrahedral and octahedral sites for each analyzed sample (see Table II). The ration value taken for the as-deposited sample [0.94 (9)] is close to the value 0.94 of the ideal ferrite, 31 indicating that our compound has the same amount of Fe in the octahedral coordination than an ideal ferrite.…”

Elimination of Escherichia coli in Water Using Cobalt Ferrite Nanoparticles: Laboratory and Pilot Plant Experiments

“…Ferrites (MFe 2 O 4 ) are magnetic materials containing ferric and M(II) ions, where M could be Co, Ni, Zn, etc. [7], and they have an inverted spinel structure. These materials have been extensively studied due to their applications in magnetic storage devices, magnetic fluids, drugs transport systems, magnetic resonance imaging, medicine, and catalysis [8,9].…”