Quadrupolar interaction in metal particulate recording media

Abstract

Interparticle interactions in metal particulate recording media were studied by experiments. A new analysis method to evaluate the magnetic interactions in the media is considered. In the present paper, differences between the normalized DC demagnetization remanence and isothermal remanent magnetization curves are interpreted as a deviation of the magnetic switching field, that is the magnetic interaction field, δ H. The parameter δ H is confirmed to be useful in evaluating quantitatively the interparticle interaction in the media. The magnetic anisotropy constant derived from the interparticle interaction can be obtained from the angular dependence of the magnetic interaction field, δ H. As a result, it is found that quadrupolar interactions play a remarkably important role in the origin of the magnetic anisotropy in metal particulate media. The magnetic anisotropy energy derived from the interparticle interaction is useful in discussing the thermal stability of the media's recorded pattern.