A reversed gyromagnetic effect in chromium dioxide particles

• Published in: Journal of magnetism and magnetic materials Vol. 260; no. 1; pp. 131 - 140
• Main Author: Madsen, Karen Nørgaard
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2003; Elsevier Science
• Subjects: Chromium dioxide; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; GRM; Maghemite; Magnetic properties and materials; Magnetic recording materials; Magnetically ordered materials: other intrinsic properties; Physics; Recording particles; RRM; Saturation moments and magnetic susceptibilities; Studies of specific magnetic materials; Recording particles; GRM; RRM; Chromium dioxide; Maghemite; Inorganic compounds; Alternating field; Transition element compounds; Magnetic moments; Binary compounds; Experimental study; Gyromagnetic effect; Magnetic particles; Asymmetry; Remanent magnetization; Anisotropy; Chromium oxides; Recording material
• ISSN: 0304-8853
• DOI: 10.1016/S0304-8853(02)01238-6

The gyromagnetic properties of CrO 2 recording particles have been investigated and compared to those of γ-Fe 2O 3, which have previously been subject to similar studies. Rotational remanent magnetization (RRM) was determined as a function of rotation speed and of the strength of the magnetizing alternating field (AF). Gyromagnetic remanent magnetization (GRM) acquired by anisotropic samples in a static experiment was measured for various peak AF as a function of the angle between the AF and the axis of anisotropy. The asymmetry of GRM curves obtained with non-saturating fields may be related to the incoherent reversal mode of the particles. While GRM (RRM) of the γ-Fe 2O 3 particles had the sign expected theoretically, the gyromagnetic remanences obtained for CrO 2 in both types of experiments were of opposite signs. Possible reasons for the reversed gyromagnetic effect are discussed.