Accession Number : AD0717691

Title :   Investigation of the Synthesis of Diamonds.

Descriptive Note : Physical sciences research papers,

Corporate Author : AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS

Personal Author(s) : Dickinson,Stanley Key , Jr

Report Date : 06 NOV 1970

Pagination or Media Count : 111

Abstract : Crystals of high chemical and mechanical perfection are required for research in electronic devices. The purpose of the research reported here was to produce diamonds for use in the fabrication of semiconducting devices. This was one portion of a laboratory-wide program investigating the utilization of diamond as a high temperature semiconductor. Diamond synthesis is explained in terms of crystallization from a super-saturated liquid. The major driving force is thermodynamic. The primary condition for synthesis is a stable diamond-liquid equilibrium in which the liquid is composed of carbon and certain metal solvents. Thermodynamic expressions are developed for describing the pertinent portions of the nickel-, cobalt-, manganese-, and iron-carbon binary systems. Temperature-composition diagrams at high pressures are drawn to show stability relationships and the allowed limits for synthesis. The theoretical model is verified by an extensive ultrah-high pressure-temperature experimental investigation. Theoretical and empirical results are employed in predicting conditions for producing high quality single crystals. (Author)

Descriptors :   (*DIAMONDS, *CRYSTAL GROWTH), (*SEMICONDUCTORS, DIAMONDS), THERMODYNAMICS, HIGH PRESSURE, PHASE DIAGRAMS, PHASE STUDIES, CARBON, NICKEL, COBALT, MANGANESE, IRON, DOPING, BORON

Subject Categories : Physical Chemistry
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE