Dogra, Sugandha and Sharma, Nita Dilawar and Singh, Jasveer and Poswal, Himanshu Kumar and Sharma, S. M. and Bandyopadhyay, A. K. (2011) High pressure behavior of nanocrystalline CeO2 up to 35 GPa: a Raman investigation. High Pressure Research, 31 (2). 292-303. ISSN 0895-7959

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Abstract

The present paper reports the results of in situ Raman studies carried out on nano-crystalline CeO2 up to a pressure of 35 GPa at room temperature. The material was characterized at ambient conditions using X-ray diffraction and Raman spectroscopy and was found to have a cubic structure. We observed the Raman peak at ambient at 465 cm−1, which is characteristic of the cubic structure of the material. The sample was pressurized using a diamond anvil cell using ruby fluorescence as the pressure monitor, and the phase evolution was tracked by Raman spectroscopy. With an increase in the applied pressure, the cubic band was seen to steadily shift to higher wavenumbers. However, we observed the appearance of a number of new peaks around a pressure of about 34.7 GPa. CeO2 was found to undergo a phase transition to an orthorhombic α -PbCl2-type structure at this pressure. With the release of the applied pressure, the observed peaks steadily shift to lower wavenumbers. On decompression, the high pressure phase existed down to a total release of pressure.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Taylor & Francis Group.
Uncontrolled Keywords:	high pressure; phase transitions; Raman spectroscopy; CeO2
Subjects:	Applied Physics/Condensed Matter Physics
Divisions:	UNSPECIFIED
Depositing User:	Mr. Abhishek Yadav
Date Deposited:	27 Dec 2012 08:19
Last Modified:	27 Dec 2012 08:19
URI:	http://npl.csircentral.net/id/eprint/930

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