A new design for an ultra-high density magnetic recording head using a GMR sensor in the CPP mode

In this paper, we present a new head design consisting of a GMR multilayer read element within the write head gap. The GMR read element operates in the CPP mode and is biased by an exchange coupled soft film acting like a permanent magnet. This design has many advantages over the conventional MR and spin-valve bead designs. The most significant advantage is that the read back voltage amplitude is virtually independent of track width. The cross-track profile is well defined. The read and write gaps are coincident and the device is relatively simple and is potentially suited to high yield manufacture. From the micromagnetic analysis, it is estimated that with this head design, recording density as high as 25 Gbits/in² can be achieved