Thermal expansion and polymorphism in a series of rubidium cesium boroleucites.

Saved in:

Bibliographic Details
Title:	Thermal expansion and polymorphism in a series of rubidium cesium boroleucites.
Authors:	M. Krzhizhanovskaya¹, R. Bubnova², V. Ugolkov², S. Filatov¹
Source:	Glass Physics & Chemistry. Jun2007, Vol. 33 Issue 3, p242-249. 8p.
Subjects:	X-ray diffraction, Polymorphism (Crystallography), Rubidium, Cesium
Abstract:	Abstract The crystal structure of the boroleucite solid solution Rb0.40Cs0.54B0.94Si2.06O6 is refined in space group I-43d by the Rietveld method with the use of the X-ray powder diffraction data. The refinement data complement the available crystal chemical characteristics of Rb1−x Cs x BSi2O6 solid solutions. The thermal expansion and phase transformations of Rb1−x Cs x BSi2O6 borosilicates are investigated in parallel by high-temperature X-ray diffraction with conventional powdered samples and by the dilatometric method with samples in the form of pressed pellets. It is demonstrated that the thermal expansion coefficients, as well as the temperatures and sequence of polymorphic transitions, which are determined from the data obtained by two methods are in close agreement. The temperature curve of the I-43d ⇄ Ia3d phase transition for the Rb1−x Cs x BSi2O6 solid solution system is constructed from the data obtained by both methods. It is shown with the use of the structural data obtained by the Rietveld method that, at temperatures above 800C, rubidium-cesium boroleucites undergo decomposition due to the release of alkali cations. [ABSTRACT FROM AUTHOR]
	Copyright of Glass Physics & Chemistry is the property of Springer Nature and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database:	Engineering Source

Description
Abstract:	Abstract The crystal structure of the boroleucite solid solution Rb0.40Cs0.54B0.94Si2.06O6 is refined in space group I-43d by the Rietveld method with the use of the X-ray powder diffraction data. The refinement data complement the available crystal chemical characteristics of Rb1−x Cs x BSi2O6 solid solutions. The thermal expansion and phase transformations of Rb1−x Cs x BSi2O6 borosilicates are investigated in parallel by high-temperature X-ray diffraction with conventional powdered samples and by the dilatometric method with samples in the form of pressed pellets. It is demonstrated that the thermal expansion coefficients, as well as the temperatures and sequence of polymorphic transitions, which are determined from the data obtained by two methods are in close agreement. The temperature curve of the I-43d ⇄ Ia3d phase transition for the Rb1−x Cs x BSi2O6 solid solution system is constructed from the data obtained by both methods. It is shown with the use of the structural data obtained by the Rietveld method that, at temperatures above 800C, rubidium-cesium boroleucites undergo decomposition due to the release of alkali cations. [ABSTRACT FROM AUTHOR]
ISSN:	10876596
DOI:	10.1134/S1087659607030091