MODELING OF YOKE GIANT MAGNETORESISTANCE HEADS

Yoke giant magnetoresistance (GMR) heads are of interest for ultrahigh density recording. To optimize the design and efficiency of these hea ds, a comprehensive model was developed in which the total efficiency is the product of ratios of several fluxes in the head structure. The model consists of a network of shunt reluctances, which provide flux p aths between the top and bottom yoke films, and series reluctances, wh ich represent the yoke and GMR sensor films plus yoke-sensor overlap c ontacts. Expressions for individual reluctances are derived from a tra nsmission line analysis of variable gap head segments, the series relu ctances of magnetic films, and an analysis of flux leakage between the yoke and sensor films. A sensitivity analysis was performed for sever al parameters. The efficiency was found to be sensitive to the throat height and the planar area of the yoke-sensor contact. The model predi cts a 53.6% efficiency for a 10 Gbit/in.(2) head with a 1 mu m throat height and a 2 mu m yoke-sensor overlap. Assuming a GMR sensitivity of 0.2%/Oe and the above efficiency, a 580 mu V p-p output will result f rom a 0.5 memu/cm(2) media. (C) 1997 American Institute of Physics.