X-ray Lang Topography and Infrared Spectroscopy in Quartz Crystals Grown Hydrothermally with Intermittent Runs
✍ Scribed by A. K. Guha; N. Annamalai; T. Kar; S. P. Sengupta
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 582 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0232-1300
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✦ Synopsis
Growth defects in Y-plates obtained from Y-bar synthetic quartz crystals, grown hydrothermally with intermittent runs, have been studied for the first time by X-ray Lang topography and infrared spectroscopy. To study the effect of interfaces on dislocation structures, the growth runs have been discontinued several (6 to 7) times by switching off the autoclaves from 30 min to 1 h. The dislocations were observed to change their directions at the generated interfaces, sometimes they stop at the in terfaces or move straight through the interfaces depending on the angles of the interfaces which are presumably low-angle grain boundaries. The percentage transmission of infrared beam has also been measured as a function of the distance traversed in the crystal. The inverse anelastic loss (Q) decreases at the interface which is due to the greater accumulation of chemical impurities and H bonded OHions at these interfaces. The effect of in-situ electric field on the topographic contrast has also been studied which reveal some interesting results on account of space charge polarization.