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arXiv 0907.3567cond-mat.mtrl-sci
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Ir(001)表面Fe单层膜的衬底诱导反铁磁性

Substrate-induced antiferromagnetism of an Fe monolayer on the Ir(001) surface

Josef Kudrnovsky, Frantisek Maca, Ilja Turek, Josef Redinger

摘要:

我们对铱的面心立方(001)表面上的铁单分子层的结构和磁稳定性进行了详细的从头计算研究。Fe-单层有很强的倾向,以反铁磁真正放松的几何形状。相反,非弛豫的Fe/Ir(001)样品具有铁磁基态。因此,通过减少Fe-Ir层间距来稳定反铁磁性,这与最近实验观察到的Fe/W(001)系统的反铁磁性形成鲜明对比,该系统也存在于理想的体截短的非弛豫几何结构中。计算的Fe/Ir(001)层弛豫与最近的LEED实验数据相当吻合。目前的研究中心周围的Fe-overlayer的Fe原子之间的对交换相互作用的Fe/Ir层间距离的函数,这使得详细了解的Fe/Ir(001)覆盖层的反铁磁性的评价。此外,我们的计算表明,真正的基态的性质可能是更复杂的,并显示一个自旋螺旋状,而不是一个c(2 × 2)-反铁磁秩序。最后,铁单层的Ir(001)表面的磁稳定性进行了比较,密切相关的Fe/Rh(001)系统。

英文摘要:

We present detailed ab initio study of structural and magnetic stability of a Fe-monolayer on the fcc(001) surface of iridium. The Fe-monolayer has a strong tendency to order antiferromagnetically for the true relaxed geometry. On the contrary an unrelaxed Fe/Ir(001) sample has a ferromagnetic ground state. The antiferromagnetism is thus stabilized by the decreased Fe-Ir layer spacing in striking contrast to the recently experimentally observed antiferromagnetism of the Fe/W(001) system which exists also for an ideal bulk-truncated, unrelaxed geometry. The calculated layer relaxations for Fe/Ir(001) agree reasonably well with recent experimental LEED data. The present study centers around the evaluation of pair exchange interactions between Fe-atoms in the Fe-overlayer as a function of the Fe/Ir interlayer distance which allows for a detailed understanding of the antiferromagnetism of a Fe/Ir(001) overlayer. Furthermore, our calculations indicate that the nature of the true ground state could be more complex and display a spin spiral-like rather than a c(2x2)-antiferromagnetic order. Finally, the magnetic stability of the Fe monolayer on the Ir(001) surface is compared to the closely related Fe/Rh(001) system.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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