Magnetic properties of the Heusler alloys Fea-xCo xMnSi

Abstract

From first-principle band structure calculations the Heusler alloys Fe 2MnSi and Co2MnSi are predicted to be half-metals, if the ferromagnetic state is assumed. In reality, however, Fe2MnSi exhibits a complex magnetic state with antiferromagnetic components, while Co 2MnSi is ferromagnetic with high Curie temperature and probably a half metal. In order to search better half-metals the alloys Fe 2-xCox MnSi are worth investigating. We have studied the magnetic properties of Fe2-xCo:cMnSi experimentally. With increasing Co concentration from x 0, the antiferromagnetic phase rapidly disappears. The saturation magnetization increases with increasing x. For x≥ 1.0 the saturation magnetizations agree well with those calculated theoretically. The dependence of the saturation magnetization on x is well described by the Slater-Pauling rule. This result suggests that Fe 2-xCoxMnSi is probably a half-metal for a wide range of x. © 2009 IOP Publishing Ltd.