Spin-tunneling magnetoresistive sensors

Magnetic sensors based on spin-dependent tunneling (SDT) have been theoreti cally simulated, fabricated, and experimentally tested. In particular, SDT sensors that possess even and odd input-output characteristics have been in troduced; designed, and studied. In-depth theoretical analysis of their sta tic and dynamic response characteristics has been carried out. It showed go od performance of the even-and the odd-type sensors up to 1 GHz and above 1 GHz, respectively. This holds much promise for ultra-fast magnetic reading . A novel type of a SDT sandwich has been developed, which simplifies the m icrofabrication procedure. A variety of such SDT structures of different co mpositions was produced and found to reveal effective coupling interaction. A magnetoresistive effect up to 28 % under magnetic field perpendicular to the easy magnetization axis has been recorded. (C) 2000 Elsevier Science S .A. All rights reserved.