Advanced spin-valve GMR head

Information and communication systems increasingly handle huge amounts of data, placing heavy demands on hard disk storage capacity and performance. Progress in the development of giant magnetoresistive (GMR) spin-valve materials and high-sensitivity spin-valve read heads has allowed a continuous increase of areal recording density in hard disk drives. This paper describes our advanced spin-valve head technology. This technology features a bottom type synthetic ferrimagnetic spin-valve with low magnetostriction. It comprises a magnetic layer, Ru interlayer, and magnetic layer sandwich as a pinned layer. It also has a specular spin-valve with specular reflection layers consisting of a layer of natural oxide or another oxide material. The synthetic ferrimagnet spin-valve and the specular spin-valve enable increased read-back output of the spin-valve head. This paper also describes our demonstration of over 100 Gbit/in² technologies at areal recording densities achieved by a high-sensitivity, double-specular spin-valve head on synthetic ferrimagnet media.