Magnetic disk apparatus with magnetic head having upper and lower magnetic cores of an electroplated thin film

Abstract

A magnetic disk apparatus includes a magnetic disk for recording information and a magnetic head which has a reproducing head and a recording head. The reproducing head comprising a lower shield film, a magnetoresistive film, a pair of electrodes and an upper shield, and the recording head comprising an upper magnetic core, a lower magnetic core, and a coil disposed between said upper magnetic core and said lower magnetic core. The upper magnetic core and the lower magnetic core include an electroplated thin film with an average crystal grain size smaller than 500 Å, and the electroplated thin film is made of Ni—Fe alloy of which Ni is 38 to 60 wt % and Fe is 40 to 62 wt %.

Dependencies are inferred from the claim text.