Holographic Atomic Images from Surface and Bulk W(110) Photoelectron Diffraction Data
Holographic Atomic Images from Surface and Bulk W(110) Photoelectron Diffraction Data
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来自表面和体 W(110) 光电子衍射数据的全息原子图像
DOI：
10.1103/physrevb.59.5857
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发表时间：
1999
影响因子：
3.7
通讯作者：
C. Fadley
中科院分区：
文献类型：
--
作者：
P. M. Len;P. M. Len;J. Denlinger;E. Rotenberg;S. Kevan;B. Tonner;Yong Chen;M. Hove;C. Fadley;C. Fadley
虽然伽柏最初提出在全息照相中使用电子来形成原子分辨率的图像，但直到最近才讨论了光电子衍射数据作为实现这一目标的实用方法。这些数据能够记录散射波的振幅和相位（相对于直接参考波），因此原则上允许原子位置的全息重建。因此，光电子全息术至少有希望提供近似的起始结构，这些结构可以通过多次散射计算与经由R因子的实验的更常规的比较来细化。在ALS光束线7.0上，对W（110）的表面和体核能级位移的W 4f{sub 7/2}光电子发射进行了测量，得到了一组前所未有的大小和质量的数据集。这些数据已被多次散射理论进行比较，并作为一个测试案例，因为W（110）表面是已知的，不表现出显着的松弛，在其层间距相对于体。作者分析了这些实验和理论结果全息，以证明的能力和局限性的光电子全息作为一种结构探针。
Although Gabor originally proposed using electrons in holography to form atomic-resolution images, it is only very recently that photoelectron diffraction data have been discussed as a practical method for achieving this. Such data enable recording both the amplitudes and phases of the scattered waves (relative to a direct reference wave), thus in principle permitting the holographic reconstruction of atomic positions. Photoelectron holography thus holds much promise of at least providing approximate starting structures that can be refined by more conventional comparisons of multiple-scattering calculations with experiment via R-factors. Criteria for optimizing the taking of such data and their holographic photoelectron diffraction patterns have been measured for surface and bulk core-level-shifted W 4f{sub 7/2} photoemission from W(110) on ALS beamline 7.0, yielding a data set of unprecedented size and quality. These data have been compared to multiple scattering theory, and used as a test case, since the W(110) surface is known not to exhibit significant relaxation in its interlayer spacings relative to the bulk. The authors have analyzed these experimental and theoretical results holographically in order to demonstrate the capabilities and limitations of photoelectron holography as a structural probe.