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First-principles computation of the vibrational entropy of ordered and disordered Pd3V

van de Walle, A. and Ceder, G. (2000) First-principles computation of the vibrational entropy of ordered and disordered Pd3V. Physical Review B, 61 (9). pp. 5972-5978. ISSN 0163-1829. http://resolver.caltech.edu/CaltechAUTHORS:WALprb00

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Abstract

Experimental as well as theoretical work indicates that the relative stability of the ordered and the disordered states of a compound may be significantly affected by their difference in vibrational entropy. The origin of this difference is usually attributed to the fact that disordering reduces the number of stiff bonds between different atomic species in favor of soft bonds between identical atomic species. The results of previous theoretical investigations, however, suggest that this simple mechanism is significantly modified as a result of local atomic relaxations. To gain further insight regarding the importance of relaxations, we employ first-principles calculations to investigate the magnitude of the vibrational entropy difference between the ordered and the disordered state of Pd3V. Our investigation reveals that bond stiffness changes due to relaxation entirely mask the large configurational dependence of vibrational entropy provided by bond stiffness differences. Our analysis also suggests a simple technique to estimate vibrational entropy based on the relationship between bond length and bond stiffness.


Item Type:Article
Additional Information:©2000 The American Physical Society Received 3 May 1999; revised 17 August 1999 This work was supported by the Department of Energy, Office of Basic Energy Sciences under Contract No. DEFG02-96ER45571. Axel van de Walle acknowledges support from the Natural Sciences and Engineering Research Council of Canada. The authors wish to thank G. Garbulsky for providing computer programs which made this work possible.
Record Number:CaltechAUTHORS:WALprb00
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:WALprb00
Alternative URL:http://dx.doi.org/10.1103/PhysRevB.61.5972
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:6708
Collection:CaltechAUTHORS
Deposited By: Archive Administrator
Deposited On:18 Dec 2006
Last Modified:04 Jan 2017 20:00

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