Preliminary Studies on the Characterization of Solution-Grown ADP Crystals

Autor: Avery T. Horton, Richard D. Deslattes, John L. Torgesen, Boris Paretzkin
Rok vydání: 1964
Předmět:
Zdroj: Advances in X-ray Analysis. 8:315-324
ISSN: 2631-3626
0376-0308
DOI: 10.1154/s0376030800003219
Popis: Large single crystals of ammonium dihydrogen phosphate (ADP) have been grown from solutions of reagent grade materials by means of precisely controlled temperature programs. We have studied the perfection of these crystals by means of double-crystal rocking curves and diffraction topographs. In the course of this study, effects associated with various techniques of sectioning and polishing specimens from these crystals were examined. A combination of string sawing and chemical polishing procedures produced specimens exhibiting the best diffraction characteristics. Results obtained from surfaces so prepared are tentatively taken as being characteristic of the bulk crystal and may be interpreted in terms of longrange strain fields and imaging of both emergent and nonemergent dislocations. In some specimens, regions of 1 cm2 or more have been found to be free of defect images and to have uniform reflectance.The perfection of some specimen pairs and the intrinsic properties of certain reflections suggest their possible application to spectroscopic problems. Some crystal pairs cut parallel to (101) planes have exhibited physical resolving powers of 104 at 8.3 Å; others cut for the 600 reflection have given 4 x 105 at 1,5 Å, These crystals deteriorate on exposure to moist laboratory air and preservation techniques had to be employed.
Databáze: OpenAIRE