Fe-C film formation by dual ion beam sputtering

Abstract

Fe-C films are formed by dual ion beam sputtering in which an ion beam irradiates the substrate during film formation. The magnetic properties and film structure of the resulting Fe-C films are investigated. As the acceleration voltage of the substrate beam increases, C concentration in the Fe-C films decreases, thereby changing the magnetostriction constant of the film from positive to negative. When films formed at an acceleration voltage of 0, 200, and 400 V are heated at 100, 300, and 400 °C, respectively, the relative permeability of each film reaches a maximum. The Fe-C film with 8 at. % C has a room-temperature saturation magnetic flux density of 2.2 T, a relative permeability of 900, and a magnetostriction constant near zero.