Optical diffraction from lattice images of alloys

Journal Article · Wed Sep 01 04:00:00 EDT 1976 · Acta Metall.; (United States)

DOI:https://doi.org/10.1016/0001-6160(76)90045-6· OSTI ID:7128719

Sinclair, R; Gronsky, R; Thomas, G

Optical diffraction patterns have been obtained from optimum lattice images of partially ordered Cu/sub 3/Au and spinodally decomposed Au--Ni alloys. These diffraction results show excellent agreement with the corresponding portions of electron diffraction patterns, indicating that a direct correlation exists between the lattice images and the atomic lattices of the alloys studied. It must be borne in mind that in general the optical diffractogram and the electron diffraction pattern may contain different information because of the contrast transfer in the electron microscope, and this will particularly affect reflections with larger scattering angles usually outside the objective aperture. Compared with conventional 100 kV selected area electron diffraction, the optical diffraction technique makes possible an outstanding improvement in field limitation, where the area contributing diffraction information may be reduced by over three orders of magnitude to 10A diameter. A quantitative analysis of the spinodal and ordering transformations by combined lattice imaging and optical diffraction provides experimental detail on an extremely localized scale. The results are in agreement with conventional experimental results and modern theories of phase transformations and illustrate an exciting new approach to gaining information about localized atomic mechanisms of phase transformations in alloys.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 7128719
• Journal Information: Acta Metall.; (United States), Journal Name: Acta Metall.; (United States) Vol. 24:9; ISSN AMETA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOY SYSTEMS
ALLOYS
BINARY ALLOY SYSTEMS
COHERENT SCATTERING
COPPER ALLOYS
DIFFRACTION
GOLD ALLOYS
IMAGES
INTERMETALLIC COMPOUNDS
LATTICE PARAMETERS
NICKEL ALLOYS
OPTICAL DISPERSION
ORDER PARAMETERS
PHASE TRANSFORMATIONS
SCATTERING