Induced and local anisotropies in amorphous CoZr–rare earth thin films containing Pr, Nd, and Tb

Abstract

Articles you may be interested inFluctuation field and time dependence of magnetization in TbFeCo amorphous rare earth-transition metal thin films for perpendicular magnetic recordingThe induced in-plane and local magnetic anisotropies of rf sputtered ͑Co 93 Zr 7 ͒ 100Ϫx RE x thin films were investigated as a function of RE content for REϭPr, Nd, and Tb by transverse biased initial susceptibility measurements at both film/air and glass/film interfaces. The deposition was performed in a magnetic field. The films exhibit a very well defined in-plane anisotropy with negligible long-range fluctuations and a small coercive field H c , in accordance with the experimental data. The overall variations of the transverse susceptibility are related to the ripple. The variations of the local anisotropy with composition were measured. Both the induced anisotropy K u and the local anisotropy K loc increase with the increasing amount of RE in the layers. A clear relationship between K u and K loc could be established. The results are discussed in terms of the single-ion anisotropy of the rare earth. While the value of K u is the same at both interfaces, the ripple constants were found to be slightly different. This last result is believed to be related to some local defects, the origin of which is also suggested. Also the coercive force is discussed and explained in terms of a theoretical model.

Tb doped CoNbZr soft magnetic films with high anisotropy field for applications in GHz frequency region

“…There are two contributions to the uniaxial anisotropy: one that comes from the CoNbZr matrix, and another from the Tb ions. According to the mechanism proposed by Calleja et al [12], the induced uniaxial anisotropy has its origin mostly in the part of the local anisotropy that comes from the single-ion anisotropy of the Tb sites via spin-orbit coupling. When this is the case, H k depends linearly on the Tb content.…”