Magnetoresistive head and manufacturing method thereof

Exchange coupling energy between an anti-ferromagnetic layer and a first ferromagnetic layer, and an anti-ferromagnetic coupling energy between the first ferromagnetic layer and a second ferromagnetic layer by way of an Ru anti-ferromagnetic coupling layer of a spin valve device are increased thereby increasing the magnetoresistance ratio and decreasing the coercivity of the free layer of the spin valve film. In an MnPt anti-ferromagnetic bottom type synthetic ferri-type spin valve film in which an underlayer, an anti-ferromagnetic layer comprising MnPt, a first ferromagnetic layer comprising CoFe, an anti-ferromagnetic coupling layer comprising Ru, a second ferromagnetic layer comprising CoFe, an intermediate non-magnetic layer comprising Cu, a free layer comprising synthetic films of CoFe and NiFe and a protective layer are stacked over a substrate, the Fe composition X in CoFeX of the first ferromagnetic layer is set as about: 20