Three-dimensional, quasi-steady-state modeling of heat transfer, flow, and segregation are carried out with a self-consistent, parallel, finite element model to analyze the effects of imperfections on a model system for the vertical Bridgman growth of cadmium zinc telluride. Even small amounts of ampoule tilting (defined as the offset between the ampoule axis from the direction of gravity) produce large asymmetries in the flow and solute segregation. However, the application of ampoule rotation, at rates far smaller than considered in prior studies, acts to restore axisymmetric segregation behavior. Thermal imperfections caused by ampoule offset in the furnace bore and ampoule distortion are also shown to yield significant three-dimensional flows and segregation asymmetry. Local heating is shown to strongly affect solute mixing and may be effective in active strategies for segregation control.
|Original language||English (US)|
|Number of pages||16|
|Journal||Journal of Crystal Growth|
|State||Published - Mar 1 2004|
Bibliographical noteFunding Information:
This work was part of the “Convention de stage” of GC, whose visit to the University of Minnesota was generously supported by a grant from Franćois Dupret, the UCL, and a Travel Award from the University of Minnesota Supercomputing Institute. Partial support was provided by the Microgravity Sciences Program of the National Aeronautics and Space Administration, the National Science Foundation under Grant No. 0201486, and a supercomputing resource allocation from the Minnesota Supercomputing Institute. We also extend thanks to Bing Dai (UM) for technical guidance provided to GC and to Georg Müller and Marc Hainke of the University of Erlangen for significant assistance with the program CrysVUN++.
- A1. Computer simulation
- A1. Convection
- A1. Heat transfer
- A1. Response
- A1. Segregation
- A2. Bridgman technique