Abstract
Quantitative low-energy electron diffraction current-voltage measurements have been utilized to determine the thermal expansion of the Mg(0001) and surfaces. The close-packed Mg(0001) surface exhibits a small thermal expansion while the more open surface has a dramatic thermal contraction in the first interlayer spacing, accompanied by an expansion in the second interlayer spacing. A comparison of this data with all other measurements of the low-temperature thermal expansion reveals a quite striking difference for open surfaces of different metals. Significant negative thermal contraction at the surface occurs only on open faces of light mass metals. A simple force constant model indicates that this behavior correlates with the ratio of thermal motion parallel and perpendicular to the surface.
- Received 23 May 2002
DOI:https://doi.org/10.1103/PhysRevB.66.245414
©2002 American Physical Society