Heat Transfer and Temperature Oscillations in Chemical Vapor Transport Crystal Growth I,

Abstract

It is shown that the temperature profile inside a closed CVT ampoule can deviate greatly from that of its external heat source. This deviation is discussed in terms of the optical and convective properties of the system. Chemical convective instability can result in temperature oscillations of up to plus or minus 25C under typical growth conditions. Depending on the relative molecular weights of the reactants and products involved, CCI can occur in temperature gradients which are either parallel or antiparallel to gravity. This is demonstrated with the transport gases TeCl4 and I2 (both of which thermally dissociate) and discussed for ReO3 transport with I2, for which temperature instabilities had been observed earlier.

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1973
Accession Number
AD0760732

Entities

People

  • F. Rosenberger
  • J. M. Olson
  • M. C. Delong

Organizations

  • University of Utah

Tags

DTIC Thesaurus Topics

  • Crystal Growth
  • Crystals
  • Energy
  • Heat Energy
  • Heat Transfer
  • Instability
  • Isotherms
  • Molecular Weight
  • Oscillation
  • Temperature Gradients
  • Transition Temperature
  • Transport Ships

Readers

  • Fluid Dynamics.
  • Molecular Photonics/Laser Physics
  • Thermal Physics or Thermal Science.