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Presenter: Mr. Michael Crowle - Department of Mechanical Engineering
Supervisor:

Date: Fri, March 15, 2002
Time: 13:30:00 - 14:30:00
Place: EOW 430

ABSTRACT

ABSTRACT

CdZnTe semiconductor crystals are being used in a wide variety of gamma-ray detector applications as well as a substrate for HgCdTe infrared detectors. High pressure Brigman is the most common method of growing single CdZnTe crystals thought it typically produces crystals with inconsistent composition uniformity and high defect dentists. Usable crystals must be mined out of material filled with grain boundaries and flaws. The Traveling Heater Method (THM) has the potential to grow single CdZnTe crystals with uniform composition and few defects. THM is not widely used due to its low growth rate leading to low productivity. The major limitation to the rate of THM crystal growth is the transport of the growth materials though the solution zone, which is facilitated by both diffusion and convection. Convection can be somewhat amplified by increasing thermal gradients. Diffusion rates however, are limited by the material properties. Large convection currents from thermal gradients have been associated with concave growth interfaces and unusable growth conditions that can lead to poor crystal quality or polycrystal development. Experiments growing crystals under microgravity to reduce convection while under the influence of a rotating magnetic field to generate controlled mixing have shown promise. This seminar outlines the design of an apparatus to grow CdZnTe in a 3mT rotating magnetic field (0 to 150 Hz). The apparatus allows for the later addition of a fixed 1.0T magnet to simulate microgravity conditions, as well as acoustic waves to aid in solution mixing.

FREE AND OPEN TO THE PUBLIC

Coffee and Cookies Will be Provided

For Further Information Please Contact: Mike Crowle 472-4214