A Quantitative Multi-layer Recording Model for Media with Arbitrary Easy Axis Orientation

Abstract

A simplified quantitative recording model, for thick media, and for media with arbitrary easy axis orientation is reported. The model is based on an extended version of the Williams and Comstock model. Solutions of the model are determined through an iterative procedure. The model employs a minimum number of adjustable parameters. Comparisons between calculations made with the model and experimental data in the time and frequency domain indicate the model has quantitative accuracy for ME tapes.

A generalized slope model for magnetization transitions

“…In general, the solutions tend to oscillate which requires some damping. This was also reported by other authors [10], [11]. The output voltage of the multilayer model can thus be determined by (11), shown at the bottom of the page, where…”

“…The effect of particle orientation degree was discussed in [11]. The model discussed in [10] uses considerable simplifications, but has been designed especially for ME tape and allows for the orientation of the easy axis to be modified. Common to all models [9]- [11] is the assumed angle dependence of the switching field, .…”

“…All of these models allow the transition center and the transition sharpness to vary as a function of depth. In addition to that [9] and [10] take partially magnetized layers into account, while the magnetization of the individual layers was assumed to be constant in [11]. Moreover, traditional slope modeling assumes a perfect alignment of the easy axes of the particles and so do the models in [9] and [10].…”

Metal Evaporated Media

“…Such recording anisotropy is a direct consequence of the tilted anisotropy of the magnetic film. The recording asymmetry of media with tilted anisotropy has successfully been explained on the basis of macroscopic recording models Krijnen et al, 1988;Nouchi et al, 1986;Richter, 1993b;Stupp et al, 1993Stupp et al, , 1994. In this section, we describe these models to provide some basic understanding of the recording physics of the obliquely evaporated media.…”

“…The discussion above gives a phenomenological description of the recording process. To evaluate quantitatively the transition width written into tilted medium, self-consistent macroscopic models have been developed based on the extension of the Williams-Comstock model (Williams and Comstock, 1971) for arbitrary axis orientation (Cumpson et al, , 1997Richter, 1993bRichter, , 1997Stupp et al, 1993Stupp et al, , 1994. The initial developments of the model were 1D Richter, 1993b;Stupp et al, 1993).…”