A giant magnetoresistance sensor for high magnetic field measurements

We used giant magnetoresistance in a magnetic field sensor able to measure large fields of up to several kG. We deposit spin valves with a magnetic mu ltilayer with perpendicular anisotropy as one ferromagnet and a material wi th in-plane anisotropy as the other ferromagnet. For magnetic fields along the film normal, the multilayer's magnetization is fixed perpendicular whil e the magnetic layer with in-plane anisotropy is rotated towards out-of-pla ne magnetization. The device response is nearly linear with applied field a nd determines both the magnitude and sign of the field, making it attractiv e for measuring large magnetic fields. (C) 2000 American Institute of Physi cs. [S0003-6951(00)02138-0].