MAGNETIC THIN FILM, AND MAGNETORESISTANCE EFFECT DEVICE AND MAGNETIC DEVICE USING THE SAME
A magnetic thin film being ferromagnetic and exhibiting large spin polarization at room temperature is provided that comprises a substrate (2) and a Co2Fe(Si1-xAlx) thin film (3) formed on the substrate (2) where 0<x<1 and wherein the Co2Fe(Si1-xAlx) thin film (3) has a L21 or a B2 structure. There may be interposed a buffer layer (4) between the substrate (2) and the Co2Fe(Si1-xAlx) thin film (3). A tunneling magnetoresistance effect device and giant magnetoresistance effect device using such a magnetic thin film exhibit large TMR and GMR at room temperature, with low electric current and under low magnetic field. Using such a magnetoresistance effect device, a magnetic device and a magnetic apparatus such as a magnetic sensor, a magnetic head or MRAM are provided.