Effect of Fe substitution on magnetic properties of antiferromagnetic Heusler alloy Ru 2 MnGe

The present study reveals that the correlation between the magnetic properties with composition x in the polycrystalline Ru2Mn(1-x)Fe(x)Ge system. Hard ferromagnetic properties appeared at the intermediate composition between antiferromagnetic Ru2MnGe with soft ferromagnetic Ru2FeGe. Ru2Mn0.6Fe0.4Ge shows an anisotropic and negative magnetoresistance (MR) effect more than 8% although the both end materials are small MR effect less than 1%. These experimental results correlate the variation in MR ratio with that of coercive field as a function of x. Moreover, the correlation is shown at the boundary of magnetism between antiferromagnetic and ferromagnetic. Therefore, the present experimental results imply that the coexistence of antiferromagnetic and soft ferromagnetic leads to induce the MR effect in this system. (C) 2011 Published by Elsevier B. V.