Size dependence of the bulk modulus of semiconductor nanocrystals from first-principles calculations

Cherian, R and Gerard, C and Mahadevan, P and Cuong, Nguyen Thanh and Maezono, Ryo (2010) Size dependence of the bulk modulus of semiconductor nanocrystals from first-principles calculations. In: Physical Review B: Condensed Matter and Materials Physics, 82 (23).

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Abstract

The variation in the bulk modulus of semiconductor nanoparticles has been studied within first-principles electronic-structure calculations using the local density approximation (LDA) for the exchange correlation. Quantum Monte Carlo calculations carried out for a silicon nanocrystal Si87H76 provided reasonable agreement with the LDA results. An enhancement was observed in the bulk modulus as the size of the nanoparticle was decreased, with modest enhancements being predicted for the largest nanoparticles studied here, a size just accessible in experiments. To access larger sizes, we fit our calculated bulk moduli to the same empirical law for all materials, the asymptote of which is the bulk value of the modulus. This was found to be within 2-10% of the independently calculated value. The origin of the enhancement has been discussed in terms of Cohen's empirical law M.L. Cohen, Phys. Rev. B 32, 7988 (1985)] as well as other possible scenarios.

Item Type:	Journal Article
Publication:	Physical Review B: Condensed Matter and Materials Physics
Publisher:	The American Physical Society
Additional Information:	Copyright of this article belongs to The American Physical Society.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	09 Mar 2011 05:12
Last Modified:	09 Mar 2011 05:12
URI:	http://eprints.iisc.ac.in/id/eprint/35877

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