Beschreibung:
<jats:p>The magnetic field determined from vanishing rotational hysteresis loss of CoCrPtB perpendicular thin film media was experimentally investigated. It was clarified that (1) in Co72Cr16Pt8B4 media with dmag of less than 200 nm and Co64Cr24Pt8B4 media with dmag of less than 100 nm, a homogeneous structure was realized, except for the existence of an initial growth region. (2) For both media, the perpendicular rotational hysteresis loss, Wr, the maximum field of Wr, Hp, and the field where Wr=0, HWr=0, increased with an increase in dmag. (3) For both media, HWr=0/Hkgrain increased with an increase in dmag and saturated at a magnitude of about 1. (4) For the medium with thin magnetic film thickness, at applied field of HWr=0&lt;H&lt;Hkgrain, a multidomain state was realized in the torque measurement in spite of no observation of loss of rotational hysteresis. This is considered to be due to the existence of thermal agitation between the multidomains.</jats:p>