High resolution synchrotron X-radiation diffraction imaging of crystals grown in microgravity and closely related terrestrial crystals

• Published in: Journal of research of the National Institute of Standards and Technology Vol. 96; no. 3; pp. 305 - 331
• Main Authors: Steiner, Bruce, Dobbyn, Ronald C., Black, David, Burdette, Harold, Kuriyama, Masao, Fripp, Archibald, Simchik, Richard
• Format: Journal Article
• Language: English
• Published: Legacy CDMS National Institute of Standards and Technology 01-05-1991; [Gaithersburg, MD] : U.S. Dept. of Commerce, National Institute of Standards and Technology
• Subjects: Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials Processing; Materials science; Methods of crystal growth; physics of crystal growth; Physics; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; Crystal growth; High resolution; Organic cation; Semiconductor materials; Crystal defect; Tin Lead Tellurides Mixed; Experimental study; Lattice parameters; Sulfates; X ray diffraction; Inorganic compound; Gallium Arsenides; Growth from vapor; Aminoacid; Growth from melt; Mercury Iodides; Microgravity; Synchrotron radiation; Organic compounds; gallium arsenide; microgravity; diffraction; mercuric iodide; synchrotron; topography; crystal growth; high resolution; lead tin telluride; triglycine sulfate
• ISSN: 1044-677X; 2165-7254
• DOI: 10.6028/jres.096.017

Irregularities in three crystals grown in space and in four terrestrial crystals grown under otherwise comparable conditions have been observed in high resolution diffraction imaging. The images provide important new clues to the nature and origins of irregularities in each crystal. For two of the materials, mercuric iodide and lead tin telluride, more than one phase (an array of non-diffracting inclusions) was observed in terrestrial samples; but the formation of these multiple phases appears to have been suppressed in directly comparable crystals grown in microgravity. The terrestrial seed crystal of triglycine sulfate displayed an unexpected layered structure, which propagated during directly comparable space growth. Terrestrial Bridgman regrowth of gallium arsenide revealed a mesoscopic structure substantially different from that of the original Czochralski material. A directly comparable crystal is to be grown shortly in space.