| abstract |
A ferromagnetic tunnel junction magnetic sensor has an insulation barrier layer (21C) which is sandwiched between two ferromagnetic layers (21A, 21B) and which includes a tunnel oxide film formed of an oxide of a supporting metal (preferably Al, Hf, Zr or Nb) layer. The insulation barrier layer has a thickness <= 1.7 nm, which is greater than a molecular layer in the form of the oxide forming the tunnel oxide film. Also claimed are: (i) a magnetic head containing the above sensor (20); and (ii) a magnetic read/write unit including a magnetic recording medium which is surface scanned by the above magnetic head. Also claimed is a method for producing the above sensor by (a) applying, onto the first ferromagnetic layer (21A), a metal layer (21C) having a thickness <= 1.7 nm, which is greater than a molecular layer of its oxide; (b) forming the tunnel oxide film by oxidising the surface of the metal layer; and (c) forming the second ferromagnetic layer (21B) on the oxidised surface of the metal layer. |