Surface structural analysis of CaF₂(111) using low-energy atom scattering spectroscopy

We determined the surface structure of cleaved CaF2(111) via atomic force microscopy and low-energy atom scattering spectroscopy for surface analyses of insulators. A pulsed 3 keV(-20)Ne(0) impinged on the sample. The backscattered particles were detected at a scattering angle of 180 degrees. It was found that (1) fluorine atoms dominated the topmost surfaces of cleaved CaF2(111) and (2) the topmost layer of fluorine atoms was located at an inward shift of 0.2 A with respect to the bulk lattice structure.