2004 年 28 巻 6 号 p. 797-801
An exchange-coupling layer consisting of a Co-Cr ferromagnetic layer laminated with a thin Ru layer on both sides was employed as a layer separating the recording layers in longitudinal HDD media. The Co-Cr-Pt-B recording layers, which are divided into sections of equal thickness, are ferromagnetically coupled via the antiferromagnetically coupled Co-Cr layer by a function of the thin Ru layers. Because of the separation of the recording layers, a reduction of about 30% in media noise was observed at 400 kFCI, and the thermal stability was the same as or better than that of the conventional type of synthetic ferrimagnetic media (SFM).