One-dimensional "pencil" disorder discovered for a class of intermetallic compounds. (General Developments).
By combining electron microscopy with powder neutron diffraction, the researchers determined that these compounds could be described as having a host periodic structure, but with one-dimensional structural channels. The channels are filled with strings of atoms, and a one-dimensional arrangement of the atoms along the strings has a periodicity that differs from the host structure. There is a weak correlation between the relative positions (phase) of the strings, i.e., the strings are largely independent of each other. In previous x-ray diffraction studies the possible existence of such disorder was proposed in order to explain unusually high temperature factors; however, the unambiguous demonstration of the phenomenon was presented in this NIST work for the first time. It is possible that the presence of the strings could impose special one-dimensional properties in a three-dimensional crystal.
CONTACT: Leonid Bendersky, (301) 975-6167; leonid. firstname.lastname@example.org or Judith Stalick, (301) 975-6223; judith.stalick@ nist.gov.
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|Publication:||Journal of Research of the National Institute of Standards and Technology|
|Date:||Jul 1, 2002|
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