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 multilayer with perpendicular anisotropy as one ferromagnet and a material with in-plane anisotropy as the other ferromagnet. For magnetic fields along the film normal, the multilayer's magnetization is fixed perpendicular while the magnetic layer with in-plane anisotropy is rotated towards out-of-plane magnetization. The device response is nearly linear with applied field and determines both the magnitude and sign of the field, making it attractive for measuring large magnetic fields. (C) 2000 American Institute of Physics. [S0003-6951(00)02138-0].