Giant magnetoresistance in narrow stripes

Abstract

A simple model for giant magnetoresistance in thin-film magnetic sandwiches was developed. Giant magnetoresistance (GMR) and anisotropic magnetoresistance (AMR) were measured using 1.5- mu m to 10- mu m-wide*70- mu m-long test structures etched from magnetic sandwiches with two magnetic films and a thin nonmagnetic conducting interlayer. Magnetic fields were applied to the sandwiches by passing current through the stripes and by applying external fields. The magnetic layers were sputtered (80-20) NiFe, NiFeCo, and CoFe films in the thickness range of 20 AA to 140 AA. The conducting interlayers were sputtered nonmagnetic films of Cu or alloys of CuNi and CuZn in the thickness range of 15 AA to 50 AA. The range of observed GMR was from 0.2% to 6%.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>