Thermal behavior of the Cu(110) surface studied by reflection anisotropy spectroscopy and scanning tunneling microscopy

The temperature dependence of the reflection anisotropy (RA) of the Cu(110) surface has been investigated over the temperature range 180 to 1060 K. The thermal behavior of the peak observed in RA spectra at 2.1 eV, known to arise predominantly from transitions between surface states at (Y) over bar, is monitored and correlated with the temperature dependent behavior of the occupied surface state. We correlate RA spectra with scanning tunneling microscopy data to observe the roughening transition induced at similar to 1000 K which is found to generate a high density of monoatomic steps and results in the irreversible loss of the 2.1 eV RA feature and an enhancement in the response around 4 eV. RA spectroscopy is shown to be a sensitive in-situ probe of thermal induced surface disorder.