DESIGN, FABRICATION, AND PERFORMANCE OF SPIN-VALVE READ HEADS FOR MAGNETIC RECORDING APPLICATIONS

Since the early 1990s, the introduction of dual-element recording head s with inductive write elements and magnetoresistive (MR) read element s has almost doubled the rate of areal density improvements for hard-d isk-drive data storage products. In the past several years, prospects of even more rapid performance improvements have been made possible by the discovery and development of sensors based on the giant magnetore sistance (GMR) effect, also known as the spin-valve effect, for a part icular class of sensor configurations. In this paper, we explore the p otentials as well as challenges of spin-valve sensors as magnetic reco rding read heads. We first examine the data rate and areal density pot entials of large read-back signals resulting from increases in the MR coefficient. We then discuss associated magnetic sensor performance, i ncluding linearity and noise suppression. Finally, we study in detail the magnetic and recording performance of a spin-valve read head desig ned for 1-Gb/in.(2) density performance.