Sharma, Nita Dilawar and Singh, Jasveer and Vijay, Aditi and Samanta, K. and Dogra, S. and Bandyopadhyay, A. K. (2016) Pressure-Induced Structural Transition Trends in Nanocrystalline Rare-Earth Sesquioxides: A Raman Investigation. Journal of Physical Chemistry C, 120 (21). 11679 -11689. ISSN 1932-7447

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Abstract

The article presents a concise review of our investigations on the preferred transition paths followed as well as high-pressure-induced structural changes in nanocrystalline rare-earth sesquioxides that include Y2O3, Sm2O3,Gd2O3, Eu2O3, Dy2O3, Ho2O3, and Yb2O3. The starting phase in all samples was predominantly cubic, as characterized using X-ray diffraction and Raman spectroscopy. The pressure-induced structural changes were primarily tracked via changes in phonon modes in the Raman spectra. The structural transition sequences demonstrated behaviors differing from the polycrystalline trends usually observed; however, it was interesting to note that the onset pressures and subsequent shifts in the phonon modes followed a trend similar to the unpressurized samples when observed with respect to the f-electron number. The mode Gruneisen parameters were estimated from the high-pressure data, which indicated a swifter response to external stimuli as the particle size reduced below an average of 50 nm. It was also inferred that the presence of traces of clisordered/nonstoichiometric material directly affected the structural transition sequence. A summary of the results and the mechanisms leading to such structural transitions is discussed.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s American Chemical Society.
Subjects:	Chemistry > Physical Chemistry Materials Science Nanoscience/ Nanotechnology
Divisions:	UNSPECIFIED
Depositing User:	Dr. Rajpal Walke
Date Deposited:	12 Apr 2018 07:31
Last Modified:	12 Apr 2018 07:31
URI:	http://npl.csircentral.net/id/eprint/2337

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