Truncation-induced multilayer relaxation of the A1(110) surface

Abstract

Results from a low-energy electron diffraction (LEED) analysis of the A1(110) surface are presented and discussed. The results indicate that a multilayer relaxation exists in the A1(110) surface region such that the spacing between layers 1 and 2 has a relative change $\ensuremath{\Delta}{d}_{12}$ of -8.5% from the bulk value, while $\ensuremath{\Delta}{d}_{23}=+5.5%$, $\ensuremath{\Delta}{d}_{34}=+2.2%$, and $\ensuremath{\Delta}{d}_{45}=+1.6%$. When these results are compared with those from an independent LEED analysis, excellent agreement is found between results for $\ensuremath{\Delta}{d}_{12}$ and $\ensuremath{\Delta}{d}_{23}$. However, a disagreement is found to exist between the results of the two analyses for $\ensuremath{\Delta}{d}_{34}$. When this disagreement is considered in relationship to predictions of a recent theory for the multilayer relaxation of metallic surfaces, the importance of future work to resolve this $\ensuremath{\Delta}{d}_{34}$ discrepancy is apparent.