DIFFUSION STUDIES IN REFRACTORY MATERIALS.

Abstract

Progress is reported in a program to investigate the effects of imposed stress and also the presence of grain boundaries on diffusion rates in magnesium oxide is described. Loads of up to 5000 psi on samples placed in four-point loading do not appear to influence the rate of diffusion of Ni(2+) in single-crystal MgO in the temperature 1000 - 1300C. Grain boundary diffusion of Ni(2+) and Co(2+) has been observed in isolated grain-boundaries in MgO bicrystals. The effect appears to be due to segregation of impurities, principally Ca(2+) and Si(4+), at the boundary, and is not an intrinsic property of the grain boundary. Data for the diffusion of Zn(2+) in MgO have been obtained, and may be described in terms of an activation energy of 1.85 electron volts and a value of D sub o of 0.0000148 sq cm/sec. (Author)

Document Details

Document Type
Technical Report
Publication Date
Feb 28, 1965
Accession Number
AD0611813

Entities

People

  • B. J. Wuensch
  • T. Vasilos

Tags

DTIC Thesaurus Topics

  • Boundaries
  • Crystals
  • Diffusion
  • Electrons
  • Energy
  • Grain Boundaries
  • Heat Of Activation
  • Impurities
  • Magnesium
  • Magnesium Compounds
  • Materials
  • Refractory Materials
  • Single Crystals

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Mechanical Engineering/Mechanics of Materials.

Technology Areas

  • Microelectronics