Patent ID: 7440238

Claim:
A thin film magnetic head comprising: a first magnetic pole and a second magnetic pole which are adjacent to a gap layer, face each other, and generate a magnetic field for magnetizing a recording medium along the surface of the recording medium; a magnetic shield layer for magnetically shielding a magnetic transducer for converting a magnetic signal to an electric signal from the periphery; and a magnetic isolation layer disposed between the first magnetic pole and the magnetic shield layer so as to be adjacent to the first magnetic pole and the magnetic shield layer, and magnetically isolating between the first pole and the magnetic shield layer, wherein the first magnetic pole is made of an iron cobalt alloy (FeCo) containing iron (Fe) in a range of 60 at % to 80 at % and having saturation magnetic flux density of 2.4 T (tesla) or higher, and the magnetic isolation layer is made of ruthenium (Ru).