MAGNETIC TUNNEL JUNCTION TYPE READ-IN HEAD, ITS MANUFACTURING METHOD AND MAGNETIC FIELD DETECTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a magnetic tunnel junction type head capable of obtaining high signal output by improving a resistance change ratio and flux guide efficiency and to provide its manufacturing method and a magnetic field detecting device. SOLUTION: The magnetic tunnel junction type head is provided with a detection surface for detecting data, a magnetic tunnel junction film 14 and a flux guide 10 extended to the detection surface from the magnetic tunnel junction film 14. The magnetic tunnel junction film 14 has a ferromagnetic free layer 20, a tunnel barrier layer 30 and a ferromagnetic pinned layer 40 and the flux guide 10 is magnetically connected with the ferromagnetic free layer 20. The flux guide 10 has saturation magnetization lower than that of the ferromagnetic free layer 20 and thus the resistance change ratio and the flux guide efficiency can be improved.