Information on grain boundary structure in nanocrystalline Pd and Cr from diffraction studies

Conference · Mon Jun 01 00:00:00 EDT 1992

OSTI ID:10164014

Eastman, J A; Thompson, L J; Satti, J ^[1]; Fitzsimmons, M R; Lawson, A C; Robinson, R A ^[2]

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1. Argonne National Lab., IL (United States)
2. Los Alamos National Lab., NM (United States)

Comparisons of diffraction data from nanocrystalline and coarse-grained Pd samples indicate that grain boundaries in nanocrystalline Pd are reasonably ordered. Lattice parameter measurements show no significant grain boundary excess volume in nanocrystalline Pd, and therefore the reduced density typically observed in nanocrystalline Pd samples must be due to porosity. The lack of any significant change in both thermal expansion coefficients and average atomic vibrational amplitudes may indicate that rigid-body motions normal to grain boundaries in nanocrystalline Pd are severely constrained. Nanocrystalline Cr shows many similarities in behavior with nanocrystalline Pd, except that significantly more non-peak intensity is observed from a nanocrystalline Cr samples than from a coarse-grained Cr sample. Impurities may account for this behavior.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38; W-7405-ENG-36
• OSTI ID: 10164014
• Report Number(s): ANL/CP-76522; LA-UR-92-3369; CONF-920670-3; ON: DE92017094
• Resource Relation: Other Information: PBD: Jun 1992
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
PALLADIUM
GRAIN BOUNDARIES
CHROMIUM
X-RAY DIFFRACTION
NEUTRON DIFFRACTION
LATTICE PARAMETERS
POROSITY
360102
STRUCTURE AND PHASE STUDIES