Uranium Atoms Don't Share the Vibe

Suppose you throw a rock into a pond, but instead of circular waves spreading across the surface, only a single bit of the surface at the rock's entry point oscillates up and down continuously. In the 31 March Physical Review Letters, researchers using the XOR 3-ID-C beamline at the APS report a surprising effect in a crystalline solid: a few-atom-wide vibration that refuses to spread through the material. The team probed heated uranium with x rays and neutrons to study the crystal's vibrations. Although predicted twenty years ago, the effect has never been conclusively seen in a three-dimensional crystal. The result seems to demonstrate the surprising ability of a uniform material to concentrate energy spontaneously. – JR Minkel

Read the entire Physical Review Focus article at: Physical Review Focus, 31 March 2006

See: M.E. Manley et al., “Formation of a New Dynamical Mode in Uranium Observed by Inelastic X-Ray and Neutron Scattering,” Phys. Rev. Lett. 96 , 125501 (31 March 2006).

Argonne National Laboratory is a U.S. Department of Energy laboratory managed by The University of Chicago

Use of the Advanced Photon Source was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. W-31-109-Eng-38

 

Figure: Localized sound modes in a uranium single crystal.

Localized sound modes in a uranium single crystal.