Temperature dependence of interlayer spacings and mean vibrational amplitudes at the Al(110) surface

The Al(110) surface has been studied by low-energy electron diffraction experiments performed in the temperature range from 40 to 890 K. The three outermost interlayer spacings, the inner potential, and the rms-vibrational amplitudes normal to the surface were determined between 40 and 450 K by a kinematical analysis of the I(E) spectra. In this temperature range a negative expansion coefficient for the first interlayer spacing and a temperature-dependent inner potential was found. At higher temperatures the mean thermal expansion coefficient was derived by the peak-shift method, taking into consideration the Debye-Waller factor and the inner potential. A strongly enhanced linear thermal expansion coefficient was observed above 750 K.