Vibrations of micro-eV energies in nanocrystalline microstructures
Abstract
The phonon density of states of nanocrystalline bcc Fe and nanocrystalline fcc Ni3Fe were measured by inelastic neutron scattering in two different ranges of energy. As has been reported previously, the nanocrystalline materials showed enhancements in their phonon density of states at energies from 2 to 15 meV, compared to control samples composed of large crystals. The present measurements were extended to energies in the micro-eV range, and showed significant, but smaller, enhancements in the number of modes in the energy range from 5 to 18 mueV. These modes of micro-eV energies provide a long-wavelength limit that bounds the fraction of modes at milli-eV energies originating with the cooperative dynamics of the nanocrystalline microstructure.
Additional Information
© 2004 The American Physical Society. Received 27 April 2004; published 10 November 2004. This work was supported by the U.S. Department of Energy under contract no. DE-FG02-03ER46055. The work at the NIST Center for Neutron Research is based upon activities supported by the National Science Foundation under Agreement No. DMR-0086210. Measurements at the Intense Pulsed Neutron Source were supported by the U.S. Department of Energy, BES-Materials Sciences, under Contract No. W-31-109-Eng-38. This work has benefited from the use of the Los Alamos Neutron Science Center at the Los Alamos National Laboratory, funded by the US Department of Energy under Contract No. W-7405-ENG-36. Certain commercial equipment, instruments, or materials (or suppliers, or software, . . .) are identified in this paper to foster understanding. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the materials or equipment identified are necessarily the best available for the purpose.Attached Files
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Additional details
- Eprint ID
- 2967
- Resolver ID
- CaltechAUTHORS:YUEprl04
- Department of Energy (DOE)
- DE-FG02-03ER46055
- NSF
- DMR-0086210
- Department of Energy (DOE)
- W-31-109-ENG-38
- Department of Energy (DOE)
- W-7405-ENG-36
- Created
-
2006-05-09Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field