Structure and Magnetic Properties of .ALPHA.'-FeCo-C Sputtered Films.

Abstract

Epitaxially grown α'-(Fe100-xCox)-C (x = 5, 10 at.%) films were synthesized by the sputtering method, and their structural and magnetic properties were investigated. The main results can be summarized as follows: (1) α'-FeCo-C single-phase films with bct crystal structure can be synthesized when prepared on MgO single-crystal substrates; (2) the saturation magnetization of α'-FeCo-C films is 5% larger than that of α'-Fe-C films; (3) α'-FeCo-C films are thermally stable up to 250°C, which is similar to the temperature for α'-Fe-C films; (4) α'-FeCo-C thin film with 5 at.% Co content shows superior soft-magnetic characteristics, and the coercive force is less than 5 Oe, which is almost identical to the value for α'-Fe-C film. Through this study, it was found that an increase in saturation magnetization can be realized by addition of 5 at.% Co to α'-Fe-C film while maintaining the latter’s thermal stability and the soft-magnetic properties.