PERMANENT-MAGNET STABILIZATION OF AN OVERLAID MR HEAD

Higher area density in the rigid disk magnetic recording industry is b eing achieved with magneto-resistive (MR) heads biased with a soft adj acent layer (SAL). The abutted and the overlaid designs are the two ap proaches most commonly used. Reader stability is a result of a single domain structure due to boundary control stabilization (BCS) from exch ange or magnetostatic coupling. The details of a particular design det ermine on track and off track performamce. Recent reviews and products suggest that the magnetostatically coupled abutted head design is sup erior to published overlaid designs. This paper describes the electric al performance and physical characteristics of another overlaid design that performs on track and off track at the recording density of 650 Mb/in(2).