Patent ID: 7463449

Claim:
A magnetic head for perpendicular magnetic recording comprising: a medium facing surface that faces toward a recording medium; coil for generating a magnetic field corresponding to data to be written on the recording medium; and a pole layer having an end face located in the medium facing surface, allowing a magnetic flux corresponding to the field generated by the coil to pass therethrough, and generating a write magnetic field for writing the data on the recording medium through the use of a perpendicular magnetic recording system, wherein: a material forming the pole layer is an alloy whose major elements are iron and nickel, and, where proportions of iron and nickel with respect to the total of iron and nickel are indicated as (100−M) weight % and M weight %, respectively, M is greater than 0 and smaller than or equal to 10; and an internal stress of the pole layer is a tensile stress; a magnetostriction constant of the material forming the pole layer is positive; where an anisotropy field of the pole layer is Hk (A/m), the magnetostriction constant of the material forming the pole layer is λ(×10 −6 ), and the internal stress of the pole layer is σ (MPa), a value of Hk/(λ×σ) is greater than 0.01 and smaller than 0.2, Hk is greater than 0 and smaller than or equal to 800, and σ is greater than or equal to 100 and smaller than or equal to 1000.