THERMODYNAMIC STUDY OF SYNTHESIS OF NEW COMPOUND PHASES UNDER HIGH PRESSURE

Abstract

A phenomological analysis and correlation of available volumetric and entropy data was performed for the III-V compounds. The results of these procedures were used to predict the volumetric properties of the known high pressure forms of BN and the unknown forms of BSb. In addition, values for compound entropy and the entropy of formation were predicted for the above compounds, BN and BSb, and for several known III-V compounds for which such data are presently lacking. The value for the P-T coefficient, was also calculated (from the predicted quantities) for the BN transformations and for the synthesis of BSb from the elements. An experimental program was carried out to attempt to synthesize a new compound BSb. The results obtained suggest that the B-Sb system at 50 kilobars is characterized by a miscibility gap in the liquid phase. High pressure experiments were also carried out for AlN; the results obtained show that solid aluminum nitride and solid boron nitride react by a diffusion process which produces marked changes in the microhardness and morphology of the boron nitride.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1967
Accession Number
AD0652828

Entities

People

  • Edward V. Clougherty
  • Larry Kaufman

Tags

Communities of Interest

  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Air Force
  • Aluminum Nitrides
  • Ceramic Materials
  • Compound Semiconductors
  • Crystal Structure
  • Elements
  • Experimental Design
  • Free Energy
  • Grain Boundaries
  • Heat Of Formation
  • High Pressure
  • Liquid Phases
  • Materials
  • Metallic Compounds
  • Miscibility
  • Phase
  • Phase Transformations

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.