New method for determining the nucleation and crystal-growth rates in classes

Citation
Cs. Ray et al., New method for determining the nucleation and crystal-growth rates in classes, J AM CERAM, 83(4), 2000, pp. 865-872
Citations number
22
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
ISSN journal
00027820 → ACNP
Volume
83
Issue
4
Year of publication
2000
Pages
865 - 872
Database
ISI
SICI code
0002-7820(200004)83:4<865:NMFDTN>2.0.ZU;2-3
Abstract
The rates for nucleation (I) and crystal growth (U) for a lithium disilicat e (Li2O . 2SiO(2), LS2) glass were determined, as a function of temperature , using a new differential thermal analysis (DTA) technique. This technique requires in situ nucleation and crystal-growth heat treatment of a small a mount of powdered sample inside the DTA apparatus, which then are followed by a DTA scan at a constant heating rate. The I and U values that have been determined at selected temperatures for the LS, glass are in excellent agr eement with those reported in the literature. The technique also has been u sed to determine the concentration of quenched-in nuclei in LS2 glasses pre pared from melts that have been quenched at different rates, which are in r easonable agreement with those estimated from theoretical considerations. T his new DTA technique is less tedious, requires a smaller amount of sample, and is at least 10 times faster than the conventional methods that have be en used to measure I and U, Also, no special sample preparation, other than simply grinding and screening the glass to a particle size that is suitabl e for use, is required in this technique, whereas grinding, polishing, or e tching is required in conventional methods. The excellent agreement in the I or U values that have been determined for the LS2 glass via the present a nd conventional methods demonstrates the accuracy, validity, and usefulness of this DTA method for rapid determination of the nucleation and crystal-g rowth rates in glasses.