标题：Half-metallicity and anisotropy magnetoresistance properties of Heusler alloys Fe_2Co_(1-x)Cr_xSi
作者：Du, Y.;Xu, G.Z.;Liu, E.K.;Li, G.J.;Zhang, H.G.;Yu, S.Y.;Wang, W.H.;Wu, G.H.
作者机构：Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, Chi
来源：Journal of Magnetism and Magnetic Materials
关键词：Anisotropy magnetoresistance;Half-metallicity;Heusler alloy
摘要：In this paper, we investigate the half-metallicity of Heusler alloys Fe_2Co_(1-x)Cr_xSi by first principles calculations and anisotropy magnetoresistance measurements. It is found that, with the increase of Cr content x, the Fermi level of Fe_2Co _(1-x)Cr_xSi moves from the top of valence band to the bottom of conduction band, and a large half-metallic band gap of 0.75 eV is obtained for x=0.75. We then successfully synthesized a series of Heusler Fe _2Co_(1-x)Cr_xSi polycrystalline ribbon samples. The results of X-ray diffraction indicate that the Fe_2Co _(1-x)Cr_xSi series of samples are pure phase with a high degree of order and the saturation magnetic moment follows half-metallic Slater-Pauling rule. Except for the two end members, Fe_2CoSi and Fe_2CrSi, the anisotropic magnetoresistance of Fe_2Co _(1-x)Cr_xSi (x=0.25, 0.5, and 0.75) shows a negative value suggesting they are stable half-metallic ferromagnets.