VECTOR MAGNETIZATION OF RECORDING MEDIA - A NEW METHOD TO COMPENSATE FOR DEMAGNETIZING FIELDS

Until now measurements of M(H) loops of thin samples have been corrected for demagnetisation after completion of the measurement. In this way it is only possible to correct for the component of the demagnetising field which is parallel to the applied field. In this paper we present a method to correct for the total demagnetising field during the measurement by simultaneously changing the strength of the applied field and rotating the sample. This method has been applied to a sample of metal-evaporated (ME) tape and a Co-Cr layer. These measurements show that the method is significantly better than existing methods. Moreover, it is shown that the intrinsic magnetic properties of the ME tape and the Co-Cr layer measured with the new method are remarkably similar.