Thin film magnetic head using soft magnetic film having soft magnetic characteristics of high resistivity, low coercive force, and high saturation magnetic flux density

A thin film magnetic head, comprising:

• a lower core layer;
• an upper core layer acting as a surface facing a recording medium which faces the lower core layer through a magnetic gap;
• and
• a coil layer for inducing a recording magnetic field to both the core layers,
• wherein at least one of the upper core layer and the lower core layer is formed of a soft magnetic film comprising Ni, Fe, O, C, and S,
• wherein the average grain size of the soft magnetic film is less than or equal to 80 Å, and
• wherein the composition of the soft magnetic film is:
• Fe is 45.44 percent by mass to 65 percent by mass, the composition ratio of O+C+S which is obtained by adding the composition ratios of O, C, and S is at least 1.73 percent by mass and at most 5.00 percent by mass, wherein the amount of O is at least 1.30 percent by mass and at most 3.70 percent by mass, the amount of C is at least 0.32 percent by mass and at most 0.90 percent by mass, the amount of S is and at least 0.15 percent by mass and at most 0.43 percent by mass, and the balance of the soft magnetic film consists of Ni.