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Directional Solidification and Characterization of Hg(0.89) Mn(0.11)TeTwo boules of Hg(0.89)Mn(0.11)Te(MMT) were solidified using the vertical Bridgman-Stockbarger method. Translation rates of 0.09 and 0. 18 microns/s were used. The influence of growth rate on axial compositional homogeneity in the MMT boules was evaluated experimentally by conducting precision density measurements on radial slices taken from each boule. In addition, Plane Front Solidification theory and segregation coefficient (k) data for the Hg(1-x)Mn(x)Te system were used to fit theoretical composition profiles to the measured MMT axial composition profiles. The strong correlation between the measured and calculated MMT axial composition profiles indicates diffusion dominated axial solute redistribution in the boules under the applied growth conditions. The analysis of the MMT axial composition profiles by Plane Front Solidification theory allowed the calculation of the effective diffusion coefficient (D(eff) = 3.5 x l0(exp -5) sq cm/s). The k-values for the Hg(1-x)Mn(x)Te system and the D(sub eff) - value were then used to verify that both boules were solidified under conditions which did not exceed the Constitutional Supercooling Criteria under ideal conditions. Finally, a preliminary examination of the radial compositional variation in each MMT was made using Fourier Transform Infra-Red Spectroscopy (FTIR). The radial homogeneity in the MMT boules was found to be comparable for both translation rates.
Document ID
19990077374
Acquisition Source
Marshall Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Price, M. W.
(Alabama Univ. Birmingham, AL United States)
Scripa, R. N.
(NASA Marshall Space Flight Center Huntsville, AL United States)
Lehoczky. S. L.
(NASA Marshall Space Flight Center Huntsville, AL United States)
Szofran, F. R.
(Alabama Univ. Birmingham, AL United States)
Su, C.-H.
(Alabama Univ. Birmingham, AL United States)
Date Acquired
August 19, 2013
Publication Date
January 1, 1998
Subject Category
Metallic Materials
Meeting Information
Meeting: Crystal Growth
Location: Jerusalem
Country: Israel
Start Date: July 26, 1998
End Date: July 31, 1998
Distribution Limits
Public
Copyright
Other

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