Structural determination of a low-symmetry surface by low-energy electron diffraction and ab initio calculations: Bi(110)

TL;DR

This study combines LEED experiments and ab initio calculations to determine the atomic structure of Bi(110), revealing a bulk-truncated surface with no reconstruction and providing insights into surface vibrational properties.

Contribution

It presents the first combined experimental and theoretical analysis of Bi(110) surface structure, confirming a (1×1) termination with no relaxation or reconstruction.

Findings

Surface is bulk-truncated with no reconstruction.

Surface Debye temperature is lower than bulk, indicating larger atomic vibrations.

Good agreement between experimental data and first-principles calculations.

Abstract

The surface structure of Bi(110) has been investigated by low-energy electron diffraction (LEED) intensity analysis and by first-principles calculations. Diffraction patterns at a sample temperature of 110 K and normal incidence reveal a bulk truncated (1$\times$1) surface without indication of any structural reconstruction despite the presence of dangling bonds on the surface layer. Good agreement is obtained between the calculated and measured diffraction intensities for this complex, low-symmetry surface containing only one mirror-plane symmetry element. No significant interlayer spacing relaxations are found. The Debye temperature for the surface layer is found to be lower than in the bulk, which is indicative of larger vibrational atomic amplitudes at the surface. Meanwhile, the second layer shows a Debye temperature close to the bulk value. The experimental results for the relaxations agree well with those of our first-principles calculation.