Polymorphism and Polytypism.

Abstract

Polymorphic transitions of binary sulfides were examined for possible differences in composition between polymorphs by direct synthesis or by the highly sensitive method of testing the transition temperature for dependence on sulfur fugacity. Experimental study of the Hg-S, Fe-S, and Ag-S systems, plus compilition of published data on 33 other binaries revealed a total of 16 transitions where temperatures and compositions (or fugacity-dependence) are sufficiently well known to determine any change in composition between polymorphs; because only one of these transitions is isocompositional, it is clear that sulfide transitions, in general, are between phases of different compositions. Consequently, definitions of polymorphs and of transitions or transformations need revision. (Modified author abstract)

Document Details

Document Type
Technical Report
Publication Date
Jan 31, 1973
Accession Number
AD0762365

Entities

People

  • Hubert L. Barnes

Organizations

  • Pennsylvania State University

Tags

DTIC Thesaurus Topics

  • Transition Temperature
  • Transitions

Readers

  • Materials Science and Engineering.