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Phase transitions in two dimensions - the case of Sn adsorbed on Ge(111) surfaces

O. Bunk·J. H. Zeysing·G. Falkenberg·R. L. Johnson·M. Nielsen·M. M. Nielsen·R. Feidenhans'l
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Abstract

Accurate atomic coordinates of the room-temperature (root3xroot3)R30degree and low-temperature (3x3) phases of 1/3 ML Sn on Ge(111) have been established by grazing-incidence x-ray diffraction with synchrotron radiation. The Sn atoms are located solely at T4-sites in the (root3xroot3)R30degree structure. In the low temperature phase one of the three Sn atoms per (3x3) unit cell is displaced outwards by 0.26 +/- 0.04 A relative to the other two. This displacement is accompanied by an increase in the first to second double-layer spacing in the Ge substrate.

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O. Bunk, J. H. Zeysing, G. Falkenberg, R. L. Johnson, M. Nielsen, M. M. Nielsen, R. Feidenhans'l. 1999-09-20. Phase transitions in two dimensions - the case of Sn adsorbed on Ge(111) surfaces. https://doi.org/10.1103/physrevlett.83.2226

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