CaltechAUTHORS
  A Caltech Library Service

Phonon density of states of nanocrystalline Fe prepared by high-energy ball milling

Fultz, B. and Robertson, J. L. and Stephens, T. A. and Nagel, L. J. and Spooner, S. (1996) Phonon density of states of nanocrystalline Fe prepared by high-energy ball milling. Journal of Applied Physics, 79 (11). pp. 8318-8322. ISSN 0021-8979. http://resolver.caltech.edu/CaltechAUTHORS:FULjap96

[img]
Preview
PDF
See Usage Policy.

120Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:FULjap96

Abstract

We performed inelastic neutron scattering measurements on nanophase Fe powders prepared by high-energy ball milling. Neutron energy loss spectra were measured for two states of the material: (1) as milled, when the material had a characteristic nanocrystallite size of 12 nm; and (2) annealed, when the material had a characteristic crystallite size of 28 nm. The longitudinal peak in the phonon density of states (DOS) of the nanophase Fe was broadened, compared to that of the annealed material. We attribute this broadening to short phonon lifetimes in nanocrystals. The nanophase material also showed an enhanced density of states at low energies below 15 meV, which may indicate the presence of intercrystallite vibrations. These differences in phonon DOS should have only a small effect on the difference in vibrational entropy of nanocrystalline and larger-grained Fe.


Item Type:Article
Additional Information:©1996 American Institute of Physics. (Received 28 December 1995; accepted 19 February 1996) The Oak Ridge National Laboratory is managed for the Department of Energy by Lockheed Martin Energy Research, Oak Ridge, TN, under Contract No. DE-AC05-96OR22464. This work was supported by the U.S. Department of Energy under Contract No. DE-FG-03-86ER45270.
Subject Keywords:IRON; PHONONS; MILLING; POWDERS; NEUTRON DIFFRACTION; INELASTIC SCATTERING; LINE BROADENING; ENERGY–LEVEL DENSITY; ENTROPY; GRAIN SIZE; PHONON SPECTRA
Record Number:CaltechAUTHORS:FULjap96
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:FULjap96
Alternative URL:http://dx.doi.org/10.1063/1.362543
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1807
Collection:CaltechAUTHORS
Deposited By: Archive Administrator
Deposited On:18 Feb 2006
Last Modified:26 Dec 2012 08:46

Repository Staff Only: item control page