A perpendicular write head design for high-density recording

In this paper, we discuss a single-pole perpendicular head design and process that is suitable for densities of the order of 100 Gb/in². The single-pole write head was integrated with a narrow-track bottom spin valve reader. The design uses a single-turn coil to generate magnetomotive force in the head. Because of the very short yoke length that is achieved by using a single-coil turn, this writer design has a very low head inductance. Low magnetic impedance of the head makes it suitable for high data rate writing. Using the finite element model (FEM), the head geometry was optimized to write on media with coercivity (H_c) of 5000 Oe. Because of the very efficient head structure, a write current below 100 mA was sufficient. As trackwidths are reduced, the field contours at the media show significant curvature, resulting in written-in transition curvature. Because of the very small yoke structure, no degradation of low-frequency amplitude up to ±90 Oe of external field is observed.