Structural, magnetic, and electronic properties of high moment FeCo nanoparticles

• Published in: Journal of alloys and compounds 2014-04, Vol.591, p.58-64
• Main Authors: Zehani, K., Bez, R., Boutahar, A., Hlil, E.K., Lassri, H., Moscovici, J., Mliki, N., Bessais, L.
• Format: Article
• Language: English
• Subjects: Alloys; Annealing; Body centered cubic lattice; Cobalt ferrites; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Density of states; Diffraction; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic structure calculations; Electronic structure of nanoscale materials : clusters, nanoparticles, nanotubes, and nanocrystals; Exact sciences and technology; Intermetallic compounds; Materials science; Materials synthesis; materials processing; Methods of nanofabrication; Nanoparticles; Physics; Polyol synthesis; Random magnetic anisotropy; Saturation (magnetic); Structural and magnetic properties
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2013.11.208

•The nanoparticles cobalt ferrite was synthesized in polyol medium (10nm).•Subsequently, the ferrite is annealed under argon at 873K for different times.•After annealing, we have obtained of nanoparticles FeCo.•Their Structural, electronic, and magnetic properties have been presented.•The sample annealed at 873K for 4h exhibits the best Ms (Ms = 235 emu g−1). Soft-magnetic Fe55Co45 alloy nanoparticles have been successfully synthesized by the polyol reduction process followed by annealing under argon. The diethylene glycol (DEG) was used as solvent and reducing agent simultaneously in this process. The synthesized samples of nanoparticles were annealed at 873K for different times. The alloy formation processes, the evolution of the microstructure, the magnetic properties, and the DOS calculation have been investigated before and after samples annealing. The X-ray diffraction of the synthesized product before annealing shows that a cobalt ferrite is spinel structure of crystallite size of about 10nm. X-ray diffraction analysis of the samples annealed at 873K for different times also shows that of the FeCo alloy has been obtained by reducing the cobalt ferrite. It has been confirmed the formation of a body-centered-cubic (bcc) single phase structure where the wt.% increases with annealing times leading to a pure phase after annealing during 4h. These results are confirmed by transmission electron microscopy study. The saturation magnetization of the Fe–Co alloys increases with annealing time, indicating an increasing homogeneity in composition and the single bcc FeCo phase formation. The highest saturation magnetization of 235emug−1with a low coercivity of 76Oe was obtained for the Fe55Co45nanoparticles annealed during 4h. The local random anisotropy constant KL has been extracted. This work presents also detailed information about total, and atom projected density of state functions, as well as the magnetic moment for different atoms in Fe55Co45 alloys and cobalt ferrite.