Author/Authors :
Ueno، نويسنده , , A. and Fujita، نويسنده , , T. and Matsue، نويسنده , , M. and Yanagisawa، نويسنده , , H. and Oshima، نويسنده , , C. and Patthey، نويسنده , , F. and Ploigt، نويسنده , , H.-C. and Schneider، نويسنده , , W.-D. and Otani، نويسنده , , S.، نويسنده ,
Abstract :
We have investigated a BC3 covered NbB2(0 0 0 1) surface using scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and low energy electron diffraction (LEED). The STM images reveal characteristic features of a Moiré pattern reflecting an incommensurate relation of the BC3 sheet with the substrate: bright protrusions with the periodicity of the substrate lattice are modulated in intensity with the periodicity of the BC3 lattice. As a result, the surface exhibits nm-scale patchy regions with either the √3 × √3 or the 1 × 1 structure of the substrate. The two-dimensional Fourier transformation pattern of the STM image is consistent with the LEED pattern proving the epitaxial and incommensurate relationship between BC3 surface sheet and substrate. No feature of a predicted superconducting gap was found in STS spectra measured at 5 K.
Keywords :
Scanning tunneling microscopy , Scanning tunneling spectroscopy , Low energy electron diffraction , BC3 , Honeycomb structure , surface structure , Thin film structure , surface segregation
