GRAIN BOUNDARY DIFFUSION IN MGO: ORIGIN OF THE EFFECT,

Abstract

Preferential diffusion of Ni(2+) and Co(2+) along grain boundaries has been observed in certain bicrystals of MgO. This enhancement is due to impurity segregation at the boundary. The impurities responsible for the effect are the principal impurities contained within the single-crystal MgO: Ca, Si, and Fe. No enhancement has been observed in any bicrystal prepared above 1300C. This temperature corresponds to that at which studies of the mechanical properties of MgO have implied a reabsorption of impurity precipitates into solid solution. It is concluded that enhanced grain-boundary diffusion of cations in MgO is an extrinsic, rather than an intrinsic property of the boundary. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1965
Accession Number
AD0628849

Entities

People

  • B. J. Wuensch
  • T. Vasilos

Tags

DTIC Thesaurus Topics

  • Boundaries
  • Crystals
  • Diffusion
  • Grain Boundaries
  • Impurities
  • Mechanical Properties
  • Precipitates
  • Single Crystals
  • Solid Solutions

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.