Accession Number : AD0682518

Title :   INVESTIGATION OF EVAPORATION AND CONDENSATION MECHANISMS.

Descriptive Note : Final rept. 16 Aug 67-15 Sep 68,

Corporate Author : TYCO LABS INC WALTHAM MASS

Personal Author(s) : Das,B. N. ; Lamport,C. B. ; Menna,A. A. ; Wolff,G. A.

Report Date : DEC 1968

Pagination or Media Count : 154

Abstract : Langmuir evaporation rates from (00.1) 'zinc' surfaces and (00.minus 1) 'oxygen' surfaces of ZnO single crystals have been determined by electromicrobalance experiments for temperatures between 900 degrees and 1300 degrees C. The theoretical evaluation of the evaporation mechanism of compounds of the type AB undergoing decomposition according to reaction 2 AB (arrow) 2 A + B2 was approached in two ways: (1) by an analysis of the various possible reaction paths, with a confining restriction imposed by the equilibrium condition, and (2) by taking into account in this analysis the limiting influence of the developing crystal morphology on the evaporation kinetics. Some general principles governing habit derivation were obtained in the course of a detailed study of the noncentrosymmetrical habit of the related chalcopyrite structure.

Descriptors :   (*CRYSTAL GROWTH, *REACTION KINETICS), EVAPORATION, CONDENSATION, CHEMICAL REACTIONS, HIGH TEMPERATURE, SINGLE CRYSTALS, SURFACES, OXIDES, ZINC COMPOUNDS, SEMICONDUCTORS, GOLD, FILMS

Subject Categories : Physical Chemistry
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE