Digital magnetoresistive sensor based on the giant magnetoresistance effect

摘要: A magnetoresistive (MR) sensor based on the giant magnetoresistance (GMR) effect provides a digital output signal. The multilayer stack of alternating ferromagnetic layers and nonferromagnetic metal spacer in GMR has an essentially single crystalline structure so that each exhibits uniaxial magnetic anisotropy, i.e. moments can lie only parallel or antiparallel to axis. Unlike multilayers where all are affected simultaneously by external field, present layer its moment responsive field strength is different from strengths at which other responsive. This allows switch magnetization direction antiparallel, vice versa, independently layers. unique property accomplished either selecting have anisotropy energy, such as varying strain during growth, subjecting value antiferromagnetic exchange coupling thicknesses As result, resistance changes stepped increments varied, thereby providing signal output. be used read head multiple data recording storage system. In one disk drive embodiment, two magnetically isolated decoupled reads written bits both simultaneously, it's then decoded conventional logic circuitry provide separate recorded