Magnetic and structural characterization of nanosized BaCo sub(x)Zn sub(2-x)Fe sub(16)O sub(27) hexaferrite in the vicinity of spin reorientation transition

• Published in: Journal of physics. Conference series 2011-01, Vol.303 (1), p.1-6
• Main Authors: Pasko, A, Mazaleyrat, F, LoBue, M, Loyau, V, Basso, V, Kupferling, M, Sasso, C P, Bessais, L
• Format: Article
• Language: English
• Subjects: Anisotropy; Barium compounds; Diffraction; Ferrites; Magnetic fields; Nanostructure; Sol gel process; Structural analysis
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/303/1/012045

Numerous applications of hexagonal ferrites are related to their easy axis or easy plane magnetocrystalline anisotropy configurations. Certain W-type ferrites undergo spin reorientation transitions (SRT) between different anisotropy states on magnetic field or temperature variation. The transition point can be tuned by modifying the chemical composition, which suggests a potential application of hexaferrites in room temperature magnetic refrigeration. Here we present the results of structural and magnetic characterization of BaCo sub(x)Zn sub(2-x)Fe sub(16)O sub(27) (0.7 [< or =] x [< or =] 2) doped barium ferrites. Fine powders were prepared using a sol-gel citrate precursor method. Crystal structures and particle size distributions were examined by X-ray diffraction and transmission electron microscopy. The optimal synthesis temperature ensuring complete formation of single W-phase with limited grain growth has been determined. Spin reorientation transitions were revealed by thermomagnetic analysis and AC susceptibility measurements.