High sensitive magnetoresistance in evaporated spin valves with growth-induced uniaxial anisotropy

A highly sensitive magnetoresistance behavior related to the well defined induced uniaxial anisotropy has been observed in a single spin valve deposited with conventional electron beam evaporation. An external magnetic field of 20 Oe (deposition field) was applied during the deposition to induce the anisotropy, which resulted in a marked increase of the MR ratio. Magnetoresistence changes of 4.1% (improved from 3.1% due to the application of the deposition field) for NiFe/Cu/Co and 6.3% for NiFe/Co/Cu/Co were obtained in a micro strip pattern prepared by an Ar ion milling through photoresist mask. A hysteresis free linear MR behavior has been realized in the patterned samples.