Thickness-dependent electronic and magnetic properties of γ′-Fe4N atomic layers on Cu(001)
Thickness-dependent electronic and magnetic properties of γ′-Fe4N atomic layers on Cu(001)
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DOI：
10.1103/physrevb.95.224417
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发表时间：
2017-06-14
影响因子：
3.7
通讯作者：
Komori, F.
中科院分区：
文献类型：
--
作者：
Takahashi, Y.;Miyamachi, T.;Komori, F.
用扫描隧道显微镜/能谱和X射线吸收光谱/磁圆二色谱研究了在铜(001)面上的γ‘-Fe4N原子层的生长、电子和磁学性质。在N-2气氛下，在单层Fe2N/Cu(001)上沉积Fe，得到了连续的三层有序的γ‘-Fe4N薄膜，而在生长周期中，0.5keV的N+离子反复轰击，得到了不完美的双层薄膜。随着样品厚度的增加，样品表面电子结构发生变化，Fe原子的自旋磁矩增强，达到与三层样品中的1.4mU(B)/原子相近。用第一性原理计算的层分辨态密度很好地解释了观察到的系统的厚度相关性质，这表明在铜(001)表面上的伽马‘-Fe4N原子层的每个表面、次表面和界面内都有强烈的层相关电子态。
Growth, electronic, and magnetic properties of gamma'-Fe4N atomic layers on Cu(001) are studied by scanning tunnelingmicroscopy/spectroscopy and x-ray absorption spectroscopy/magnetic circular dichroism. Acontinuous film of ordered trilayer gamma'-Fe4N is obtained by Fe deposition under N-2 atmosphere onto monolayer Fe2N/Cu(001), while the repetition of a bombardment with 0.5 keV N+ ions during growth cycles results in imperfect bilayer gamma'-Fe4N. The increase in the sample thickness causes the change in the surface electronic structure, as well as the enhancement in the spin magnetic moment of Fe atoms reaching similar to 1.4 mu(B)/atom in the trilayer sample. The observed thickness-dependent properties of the system are well interpreted by the layer-resolved density of states calculated using first principles, which demonstrates the strongly layer dependent electronic states within each surface, subsurface, and interfacial plane of the gamma'-Fe4N atomic layers on Cu(001).