Physical configuration of Ar molecules on metal-oxide surfaces

Abstract

A combined thermodynamic and structural investigation of the interaction of argon with a MgO (100) surface was made. Ar gas adsorption isotherm studies recorded below the triple point showed the formation of at least two atomic layers of argon in the temperature above 77 K. Synchrotron X-ray diffraction (XRD) data were also recorded from a monolayer film of argon on MgO (100) surface for a series of different temperatures at the 5A-HFMS beamline of the Pohang Synchrotron Light Source in Korea. X-ray diffraction peaks from the Ar atomic layer were measured by taking the difference spectra between monolayer coverage and no argon coverage. Analyzing the data suggested that the Ar molecules form an 1 x 1 structure on the MgO (100) surface.