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 III-V compounds. The results of these procedures were used in the design of high pressure synthesis experiments to attempt to stabilize and retain the compound BSb. Thermodynamic data were calculated for certain III-V compounds for which such data have not been measured. The experimental results for the study of the B-Sb system at 30 and 50 kilobars suggest that a miscibility gap occurs in the liquid phase which prohibits the synthesis of BSb although pressure stabilization of the compound is predicted. An experimental survey of selected chemical stoichiometries which are Group IV element analogues and hence according to Hall and Compton candidate systems for new tetrahedral materials was conducted at 30 and 50 kilobars and elevated temperatures. No new materials were found at the selected stoichiometries but a new pressure stabilized phase, delta A2S3 was synthesized. An investigation of ternary systems containing the binary Group IV element analogue combination and a Group IV element showed that tetrahedral structures can be stabilized in this way. Attempts to stabilize the A2S3 stoichiometry with Ge to form Al2SGe were unsuccessful. A new high pressure stabilized phase with a NaCl cubic structure was produced in the Mo-C-N system.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1968
Accession Number
AD0670561

Entities

People

  • Edward V. Clougherty
  • Larry Kaufman

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Air Force
  • Analogs
  • Artificial Intelligence
  • Chemical Analysis
  • Chemical Compounds
  • Chemical Synthesis
  • Chemistry
  • Crystal Lattices
  • Crystal Structure
  • Heat Of Formation
  • Hot Pressing
  • Liquid Phases
  • Materials
  • Phase Transformations
  • Sodium Compounds
  • Thermodynamic Properties
  • Transition Metals

Fields of Study

  • Materials science

Readers

  • Combustion science or combustion engineering.
  • Materials Science and Engineering.
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.