SMALL-DH(C) DT CHARACTERISTICS OF COPT GRANULAR AND THIN-FILM RECORDING MEDIA/

The temperature dependence of the coercivity H-c was measured for CoPt -based thin film, CoPt-SiO2 granular film and CoCr-hased thin film rec ording media. All the samples showed a linear decrease in H-c with tem perature, -dH(c)/dT. It is found that CoPt-based media have smaller -d H(c)/dT values than CoCr-based one, This means that CoPt-based media h ave good stability for archival and read/write characteristics at elev ated temperatures. From a theoretical discussion, it is also found tha t CoPt-based thin film and granular media with small activating magnet ic moment value are expected to have smaller recording coercivity than CoCr-hased media.