Synchrotron white beam x-ray topography characterization of structural defects in microgravity and ground-based CdZnTe crystals

Hua Chung; Balaji Raghothamachar; Michael Dudley; David J. Larson Jr.

doi:10.1117/12.244357

12 July 1996 Synchrotron white beam x-ray topography characterization of structural defects in microgravity and ground-based CdZnTe crystals

Hua Chung, Balaji Raghothamachar, Michael Dudley, David J. Larson Jr.

Author Affiliations +

Proceedings Volume 2809, Space Processing of Materials; (1996) https://doi.org/10.1117/12.244357
Event: SPIE's 1996 International Symposium on Optical Science, Engineering, and Instrumentation, 1996, Denver, CO, United States

Abstract

In a microgravity environment, gravity-dependent effects such as buoyancy, convection and hydrostatic pressure are minimized, providing an ideal environment for investigating diffusion-controlled, nonwetting crystal growth processes. To evaluate the influence of microgravity on the resultant crystal quality, Synchrotron white beam x-ray topography is applied to characterize defect structures in both flight and ground-based CdZnTe single crystals. Transmission x-ray topographs recorded from one flight sample revealed regions of very low dislocation density with individual dislocations clearly resolved. Dislocations of very high density arrayed na mosaic pattern were observed in all ground-base samples grown under identical growth conditions except for the gravity conditions. This observation indicates that the flight samples have much higher structural perfection than the ground-based samples. On the other hand, studies of defect configurations in a different flight sample revealed that structural defects and distributions can be strongly influenced by rapid cooling, thermal gradients, and constrained growth. Large thermal stresses induced by rapid cooling can be multiplied by wall contact leading to the formation of extensive slip bands and small angle tilt boundaries starting at the crystal periphery and propagating into the interior of the sample. It is concluded that an optimization of post solidification cooling rate is important to minimize the occurrence of slip.

Citation Download Citation

Hua Chung, Balaji Raghothamachar, Michael Dudley, and David J. Larson Jr. "Synchrotron white beam x-ray topography characterization of structural defects in microgravity and ground-based CdZnTe crystals", Proc. SPIE 2809, Space Processing of Materials, (12 July 1996); https://doi.org/10.1117/12.244357

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available