MAGNETIC FIELD SENSOR

摘要

A magnetoresistive sensor is disclosed, which comprises of at least set of film layers, which set in turn comprises of a substrate layer (NM1), a first ferromagnetic layer (FM1), an intermediate layer (NM2) and a second ferromagnetic layer (FM4) placed on top of each other in a superlattice structure. The first ferromagnetic layer (FM1), preferably formed of iron, has a magnetisation parallel to the layer, in-plane, while the second ferromagnetic layer (FM4), formed of cobalt, has a magnetisation substantially perpendicular to the layer, out-of-plane. The ferromagnetic layers (FM1, FM4) are preferably tetragonally distorted epitaxially grown crystals, which are grown on the substrate and intermediate layers (NM1, NM2), respectively. The substrate and intermediate layers (NM1, NM2) are preferably crystalline layers of V, Cu, Ag, Au, Pd, Pt, Rh, Ru or Ir, which causes a distortion of the Fe layer corresponding to a c/a ratio of between 0.80 and 0.96 and of the Co layer corresponding to a c/a ratio of between 0.78 and 0.96. All layers are preferably very thin, most preferably less than 6-7 atomic layers.