Highly sensitive giant magnetoresistive sensor consisting of NiO spin-valve element and AC bias current line

We proposed a new sensitive giant magnetoresistive sensor consisting of a m ultilayered structure including a spin-valve element and an AC bias current line. Micro patterned spin-valve film exhibits a step-shape MR loop, in wh ich foe layer magnetization switches like a single domain. High sensitivity is attained utilizing only the edge of this MR loop. The magnetic field in duced by the bias current was set to be slightly smaller than the rising fi eld of the MR loop. The sensor detected an external field change of 0.5 Oe, and operated using a bias current having a pulse width of 30 ns. (C) 1999 Elsevier Science B.V. All rights reserved.