Date of Award
10-1977
Document Type
Dissertation - Restricted
Degree Name
Doctor of Philosophy (PhD)
Department
Mechanical Engineering
First Advisor
Robert F. Brebrick
Second Advisor
Robert N. Blumenthal
Third Advisor
Walter M. Hirthe
Fourth Advisor
Martin A. Seitz
Fifth Advisor
Peter H. Wackman
Abstract
One problem in the fabrication of electronic devices from multi-constituent, semiconducting compounds is the possible presence of multiple phases. Another problem that occurs, even when a simple phase is obtained is the control of the electrical characteristics of the resulting material. It has been observed that compositional changes too small to be accomplished through weighing can· alter the electrical characteristics of a single phase material. This results from the compositional effect on the concentration of nonstoichiometric defects which can strongly influence the electrical characteristics. The control of these defect concentrations can be accomplished thermodynamically by constraining the temperature and equilibrium partial pressures ·of the constituent vapor species over the material during a post-growth anneal.
One material that requires this careful control of the defect concentration is the mercury-cadmium-tellurium alloy in the solid solution region along the HgTe-CdTe pseudobinary plane. The usefulness of this material as an infrared detector has been well established and a desire to prepare and control this material over a broader range of compositions exists. To date the available thermodynamic data for the mercury-cadmium-tellurium system is incomplete. This investigation sought to establish some of· the data for a particular composition (x = .416, y = .5) in the (Hg1-xCdx)yTe1-y alloy.