Modification of the Magnetic Properties of Co2Y Hexaferrites by Divalent and Trivalent Metal Substitutions

• Published in: Solid state phenomena Vol. 241; pp. 93 - 125
• Main Authors: Awawdeh, Mufeed, Mohsen, Osama E., Mahmood, Sami H., Zaqsaw, Muna D., Bsoul, Ibrahim, Mohaidat, Qassem I., Awadallah, Ahmad
• Format: Journal Article
• Language: English
• Published: Zurich Trans Tech Publications Ltd 01.10.2015
• Subjects: Mössbauer Spectroscopy; Y-Type Hexaferrite; Structural Properties; Magnetic Properties
• ISSN: 1012-0394; 1662-9779; 1662-9779
• DOI: 10.4028/www.scientific.net/SSP.241.93

The present study is concerned with the fabrication and characterization of Me2Y substituted hexaferrites, Ba2Me2Fe12-xTxO22 (Me = Co2+, Mg2+, and Cr2+, and T = Fe3+, and Ga3+). The samples were prepared by the conventional ball milling technique and sintering at 1200° C. The effect of the choices of Me and T ions on the structural and magnetic properties of the hexaferrites were investigated. XRD patterns, magnetic parameters, and Mössbauer spectra of the Co2Y were consistent with a single phase Y-type hexaferrite. However, the CoCr-Y sample was found to be dominated by the Y-type hexaferrite, and M-type and BaCrO4 minority phases were observed in the XRD pattern of the sample. The small increase in saturation magnetization from about 34 emu/g up to 37.5 emu/g was therefore attributed to the development of the M-type phase. On the other hand, XRD pattern of the Cr2Y sample indicated the dominance of the M-type phase in this sample. The high coercivity (1445 Oe) of this sample is evidence of the transformation of the material from a typically soft magnetic material (Y-type) to a hard magnet (M-type). The Ga-substitution for Fe in Co2Y did not affect the saturation magnetization significantly, but the coercivity was reduced. However, the sample Ba2CoMgFe11GaO22 exhibited a significant reduction of the saturation magnetization down to a value 26.6 emu/g, which could be due to the attenuation of the super-exchange interactions induced by the Mg2+ substitution.