A Technique of the Easy Axis Distribution Measurement in Perpendicular Recording Media Part I

Abstract

This paper is to purpose the technique for the measurement of the easy axis distribution of perpendicular recording media (PRM) which is capable of supporting a high areal densitiy of 1 Tbit/in2. The several techniques which have been investigated the distribution can be separated into 2 methods by the crystallography texture using X-ray rocking curve and the magnetic measurement. The important factors affecting the easy axis distribution are exchange interactions and magnetostatic which are not evident in the variation of crystalline technique. Hence, the magnetic measurement is preferred for the measurement of easy axis distribution. In the past, the traditional remanence method used to measure the distribution for longitudinal recording media has been applied for PRM. But this method cannot be used due to the effect of large demagnetising field which is the most difficult to correct. Therefore, the variation of coercivity technique has been purposed to measure the easy axis distribution. The advantage of this technique is that the large demagnetising field is zero at the coercivity.