To suppress the decrease of the amount of a magnetic flux inside a magnetic material with respect to a high frequency signal even if the film thickness of a magnetic film in a plane facing a magnetic recording medium is made two times as large as the surface permeation depth s.
In this thin film magnetic head, a first magnetic core 16 and a second magnetic core 12 formed surrounding an electric conductor that generates a magnetic field of a magnetic recording signal are provided, the first magnetic core and the second magnetic core are connected to each other at a part away from a magnetic recording medium and are arranged with a magnetic gap 20 held at a part facing the magnetic recording medium, and a surface facing a magnetic recording medium of the first magnetic core is formed, being smaller than a surface facing a magnetic recording medium of the second magnetic core. In the facing surfaces of the magnetic recording media, width Tw that regulates the track width Tw and film thickness t of the first magnetic core are set so as to satisfy Tw≤2s≤t condition when the skin permeation depth of a magnetic flux with the maximum recording frequency f of a magnetic recording signal as a parameter is defined as s(s =√(2p/ωμ), wherein p is resistivity of the first magnetic core, ω=2πf, and μ is magnetic permeability). The first magnetic core contains Fe alloy having 40 to 60% Ni in weight.
SANO MASAAKI
WATANABE KATSURO
KAWABE TAKASHI
NAKAZAWA MANAMI
OTSU TAKAYOSHI
