Magnetoresistance effect head having a giant magnetoresistance effect film

摘要

A magnetoresistance effect head comprises a giant magnetoresistance effect film, a pair of leads to supply an electric current to the giant magnetoresistance effect head, and upper and lower magnetic shielding layers made of a crystalline soft magnetic film and disposed to hold the giant magnetoresistance effect film therebetween with a magnetic gap film intervened, wherein the surface roughness of an under layer of the giant magnetoresistance effect film is determined so that a center period L of the surface roughness satisfies L>70 nm.