MAGNETIC FIELD SENSOR WITH PERPENDICULAR AXIS SENSITIVITY, COMPRISING A GIANT MAGNETORESISTANCE MATERIAL OF A SPIN TUNNEL JUNCTION

摘要

It is proposed to make thin film magnetic field sensors with perpendicular axis sensitivity, based on a giant magnetoresistance material or a spin tunnel junction, by making use of ferromagnetic layers that have strongly different uniaxial anisotropies and/or have a modified magnetization curve by antiferromagnetic exchange coupling with an auxiliary ferromagnetic layer. ;A strongly miniaturizable magnetic field sensor is based on four spin tunnel junctions, together forming a Wheatstone bridge. The magnetically sensitive electrode functions as well as a laminated flux concentrator, resulting in a low noise single domain configuration. The very simple design also allows easy definition of the fixed magnetization direction of the counter electrode. Very high output voltage combined with very low power.