STRUCTURE DETERMINATION OF ULTRATHIN NBSE2 FILMS BY GRAZING-INCIDENCEX-RAY-DIFFRACTION

Grazing incidence x-ray diffraction (GID) technique was applied to det ermine the three dimensional structures of NbSe2 films grown by van de r Waals epitaxy. Atomic arrangements along the surface normal in nm-or der films were established from the analysis of Bragg rod profiles mea sured with GID. The obtained structural polytypes of the films grown o n HOPG and Se terminated GaAs(111BAR) were 2Hb and a mixture of 2Hb an d 3R, respectively. This result indicates that the polytypes are contr olled by the substrate materials in van der Waals epitaxy.