Electron Surface Melting

The performance of devices like transistors and memory chips depends on controlling the behavior of electrons at surfaces and interfaces of complex structures. Using surface x-ray scattering techniques, researchers at Brookhaven and Argonne National Laboratories have shown in certain oxide compounds that ensembles of electrons ‘freeze’ and ‘melt’ in ways analogous to the melting of ordinary ice. On heating, the surface of crystalline ice melts before the bulk, a phenomenon that allows skiers to glide across snow. What if electrons are the elements of the crystal lattice instead of water molecules? They too can freeze into ordered arrays at very low temperatures. The researchers studied such frozen electronic order at the surface of an oxide material just below the temperature at which it would begin to melt in the bulk. They found that the electronic surface pre-melted, while the bulk remained frozen, establishing electronic surface melting. This result has important implications for future electronic devices that require well-defined electronic interfaces, and particularly for nanoscaled devices, whose performance is dominated by their surface electronic behavior.

The work will appear in the 15 October 2011 issue of Physical Review B, where it is an Editor’s Suggestion: S. B. Wilkins et al., Phys. Rev. B. 84 165103 (2011).
This work was supported by the U.S. Department of Energy Office of Science.

 

Related Links

  1. Published paper URL: http://link.aps.org/doi/10.1103/PhysRevB.84.165103
  2. Editor Suggestions: http://prb.aps.org/#suggestions