Spatial distribution of electrons near the Fermi level in the metallic LaB6 through accurate X-ray charge density study

作者：Kasai Hidetaka; Nishibori Eiji^*

来源：Scientific Reports, 2017, 7(1): 41375.

DOI：10.1038/srep41375

Charge densities of iso-structural metal hexaborides, a transparent metal LaB6 and a semiconductor BaB6, have been determined using the d > 0.22 angstrom ultra-high resolution synchrotron radiation X-ray diffraction data by a multipole refinement and a maximum entropy method (MEM). The quality of the experimental charge densities was evaluated by comparison with theoretical charge densities. The strong inter-octahedral and relatively weak intra-octahedral boron-boron bonds were observed in the charge densities. A difference of valence charge densities between LaB6 and BaB6 was calculated to reveal a small difference between isostructural metal and semiconductor. The weak electron lobes distributed around the inter B-6 octahedral bond were observed in the difference density. We found the electron lobes are the conductive pi-electrons in LaB6 from the comparison with the theoretical valence charge density. We successfully observed a spatial distribution of electrons near the Fermi level from the X-ray charge density study of the series of iso-structural solids.

• 出版日期2017-1-25