Magnetic and structural characterization of nanosized BaCo_xZn_{2-x}Fe_{16}O_{27} hexaferrite in the vicinity of spin reorientation transition

Alexander Pasko (1, 2) , Frédéric Mazaleyrat (1, 3) , Martino Lobue (4) , Vincent Loyau (1) , Vittorio Basso (5) , Michaela Küpferling (5) , Carlo Sasso (5) , Lotfi Bessais (2)

1 SATIE - Systèmes et Applications des Technologies de l'Information et de l'Energie
2 ICMPE - Institut de Chimie et des Matériaux Paris-Est
3 IDA - Institut d'Alembert
4 SATIE-MME - Matériaux Magnétiques pour l'Energie
5 INRiM - Istituto Nazionale di Ricerca Metrologica

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_xZn_{2-x}Fe_{16}O_{27} (0.7 ≤ x ≤ 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.

Mots clés: Condensed matter: electrical; magnetic and optical; Nanoscale science and low-D systems; Condensed matter: electrical

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Alexander Pasko, Frédéric Mazaleyrat, Martino Lobue, Vincent Loyau, Vittorio Basso, et al.. Magnetic and structural characterization of nanosized BaCo_xZn_{2-x}Fe_{16}O_{27} hexaferrite in the vicinity of spin reorientation transition. Journal of Physics: Conference Series, 2011, 303 (1), pp.012045. ⟨10.1088/1742-6596/303/1/012045⟩. ⟨hal-00643884⟩