DETERMINATION OF THE SURFACE DEBYE TEMPERATURE OF MO(112) USING VALENCE-BAND PHOTOEMISSION

The temperature dependence of the valence-band emission from the (112) surface of molybdenum has been studied with ultraviolet photoemission spectroscopy. Valence-band features arising from the bulk and surface states exhibit different temperature dependences. The results can be explained in terms of bulk and surface vibrational disorder. A surface (bulk) Debye temperature of 313 K (422 K) is extracted from the data. These numbers will be compared to surface Debye temperatures measured with different techniques and on other materials. The conclusion is t hat there are major inconsistencies in the reported ratio of the surfa ce to bulk Debye temperature, presumably as a result of the approximat ions used to include thermal motion in the analysis.