NEUTRON DIFFRACTION STUDIES OF THE ORDER OF THE ATOMS IN THE P PHASE AND THE R PHASE,

Abstract

The ordering of the atoms in two ternary alloys, P phase (Mo-Ni-Cr) and R phase (Mo-Fe-Mn), both structurally related to the sigma phase, has been studied by powder neutron diffraction. The at.% Mo on each site was taken to be approximately that determined in previous X-ray single-crystal studies, which showed that Mo preferentially occupies CN16 and CN15 sites. From the best fit between observed and calculated neutron diffraction diagrams it is apparent that, in the P phase, Ni preferentially occupies CN12 positions. In the R phase, Mn shows only a slight preference for CN14 and CN15 positions over CN12 positions when competing with Fe. The results are consistent with those of ordering studies of related transition element intermetallic compounds. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 06, 1964
Accession Number
AD0614149

Entities

People

  • Clara B. Shoemaker
  • David P. Shoemaker
  • John Mellor

Organizations

  • Massachusetts Institute of Technology

Tags

DTIC Thesaurus Topics

  • Alloys
  • Crystals
  • Diffraction
  • Elements
  • Intermetallic Compounds
  • Neutron Diffraction
  • Single Crystals
  • Transition Metals
  • Transitions
  • X Rays

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Molecular Photonics/Laser Physics