Determination of first and second magnetic anisotropy constants of magnetic recording media

We propose a simple method to evaluate the first and second magnetic anisot ropy constants of high-density magnetic recording media with their easy axi s in the film plane. By measuring the magnetization curve along the film no rmal, uniaxial anisotropy constants K-1 and K-2 can be determined simultane ously. The present method has been applied to (11.0) oriented CoCrPtTa hard disk media. The measured anisotropy constants are presented along with the ir temperature dependence. We also point out serious shortcomings of the cu rrently used evaluation methods, such as the rotational hysteresis method a nd the singular point detection technique, which usually overestimate the m agnetic anisotropy constant. (C) 2000 American Institute of Physics. [S0003 -6951(00)03437-9].