FeGe纳米线中外延应力导致的铁磁性

Epitaxial stabilization of ferromagnetism in FeGe nanowires

对在Ge(111)表面沿着<11-0>方向外延生长的单斜FeGe纳米线进行研究,结果发现,虽然块体单斜FeGe相是反铁磁性,其纳米线却在200K以下表现出强铁磁有序.每个Fe原子的磁矩为0.8μB.密度泛函计算揭示外延产生的晶格压缩使类派尔斯反铁磁基态失稳,从而稳定实验观察到的铁磁性.

Epitaixial monoclinic FeGe nanowires have been grown on Ge （ 111 ） along the 〈 111 〉 direction. Whereas monoclinic FeGe is antiferromagnetic in the bulk, the nanowires are surprisingly strong ferromagnets below～200 K, with an average magnetic moment of O. 8 μB per Fe atom. Density functional calculations indicate that the observed ferromagnetism is stabilized by lattice compression, which destabilizes the antiferromagnetic Peierls- like ground state.