Temperature dependence of low energy electron diffraction from aluminum

• Published in: Surface science 1972-01, Vol.32 (1), p.139-148
• Main Authors: Quinto, Dennis T., Holland, B.W., Robertson, W.D.
• Format: Article
• Language: English
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(72)90124-0

The temperature dependence of diffracted intensity from the clean (100) surface of aluminum has been measured in the range of 298 to 598°K. Effective Debye temperatures have been extracted from the data for five prominent intensity peaks of integral and nonintegral order. It appears that all the effective Debye temperatures, which range from 189 to 331°K, are represented best by an increasing, almost linear, function of energy from 25 to 130 eV. The increase with energy is interpreted in terms of a larger mean square displacement of surface ions relative to the bulk with the result that there is a decreasing contribution from the surface with increasing energy and a corresponding rise in effective Debye temperature. More significantly, it is shown that the temperature dependence of intensity may be used to identify the operative scattering processes in terms of the order of back scattering contributing to the temperature dependence of intensity profiles. Thus, the temperature dependence of intensity maxima from aluminum indicates that they can be described by a calculation to first order in back scattering, as indeed they have been. On the other hand, the more complicated temperature dependence of diffracted intensity from copper, for example, can be identified in advance with higher orders of multiple scattering that will require calculations to higher order for its description.