GMR ANGLE DETECTOR WITH AN ARTIFICIAL ANTIFERROMAGNETIC SUBSYSTEM (AAF)

A magnetoresistive GMR sensor scheme for detection of angular position s is demonstrated and analyzed in which the hard magnetic layers are r eplaced by artificial antiferromagnetic subsystems (AAFs). These consi st of ferromagnetic layers (Go) that are antiferromagnetically coupled via interlayers (Cu or Ru). The rigidity of this AAF is improved by a n order of magnitude as compared to the individual Co layers. Operatio nal field windows for 360 degrees angle detectors of 15-20 kA/m have b een realized. The maximal sensor signal Delta rho/rho is 6%. The tempe rature operation range extends up to 150 degrees C. The angle resoluti on is about 1 degrees.