Thermodynamic properties of model CdTe/CdSe mixtures
Abstract
We report on the thermodynamic properties of binary compound mixtures of model groups II–VI semiconductors. We use the recently introduced Stillinger–Weber Hamiltonian to model binary mixtures of CdTe and CdSe. We use molecular dynamics simulations to calculate the volume and enthalpy of mixing as a function of mole fraction. The lattice parameter of the mixture closely follows Vegard's law: a linear relation. This implies that the excess volume is a cubic function of mole fraction. A connection is made with hard sphere models of mixed fcc and zincblende structures. We found that the potential energy exhibits a positive deviation from ideal soluton behaviour; the excess enthalpy is nearly independent of temperatures studied (300 and 533 K) and is well described by a simple cubic function of the mole fraction. Using a regular solution approach (combining non-ideal behaviour for the enthalpy with ideal solution behaviour for the entropy of mixing), we arrive at the Gibbs free energy of the mixture. The Gibbs free energy results indicate that the CdTe and CdSe mixtures exhibit phase separation. The upper consolute temperature is found to be 335 K. Finally, we provide the surface energy as a function of composition. Moreover, it roughly follows idealmore »
- Authors:
-
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Univ. of New Mexico, Albuquerque, NM (United States)
- Univ. of New Mexico, Albuquerque, NM (United States)
- Publication Date:
- Research Org.:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Org.:
- USDOE National Nuclear Security Administration (NNSA)
- OSTI Identifier:
- 1145705
- Report Number(s):
- SAND-2014-4246J
Journal ID: ISSN 0892-7022; 518363
- Grant/Contract Number:
- AC04-94AL85000
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Molecular Simulation
- Additional Journal Information:
- Journal Volume: 42; Journal Issue: 1; Journal ID: ISSN 0892-7022
- Publisher:
- Taylor & Francis
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; semi-conductor; mixtures; thermodynamics
Citation Formats
van Swol, Frank, Zhou, Xiaowang W., Challa, Sivakumar R., and Martin, James E. Thermodynamic properties of model CdTe/CdSe mixtures. United States: N. p., 2015.
Web. doi:10.1080/08927022.2015.1007051.
van Swol, Frank, Zhou, Xiaowang W., Challa, Sivakumar R., & Martin, James E. Thermodynamic properties of model CdTe/CdSe mixtures. United States. https://doi.org/10.1080/08927022.2015.1007051
van Swol, Frank, Zhou, Xiaowang W., Challa, Sivakumar R., and Martin, James E. Fri .
"Thermodynamic properties of model CdTe/CdSe mixtures". United States. https://doi.org/10.1080/08927022.2015.1007051. https://www.osti.gov/servlets/purl/1145705.
@article{osti_1145705,
title = {Thermodynamic properties of model CdTe/CdSe mixtures},
author = {van Swol, Frank and Zhou, Xiaowang W. and Challa, Sivakumar R. and Martin, James E.},
abstractNote = {We report on the thermodynamic properties of binary compound mixtures of model groups II–VI semiconductors. We use the recently introduced Stillinger–Weber Hamiltonian to model binary mixtures of CdTe and CdSe. We use molecular dynamics simulations to calculate the volume and enthalpy of mixing as a function of mole fraction. The lattice parameter of the mixture closely follows Vegard's law: a linear relation. This implies that the excess volume is a cubic function of mole fraction. A connection is made with hard sphere models of mixed fcc and zincblende structures. We found that the potential energy exhibits a positive deviation from ideal soluton behaviour; the excess enthalpy is nearly independent of temperatures studied (300 and 533 K) and is well described by a simple cubic function of the mole fraction. Using a regular solution approach (combining non-ideal behaviour for the enthalpy with ideal solution behaviour for the entropy of mixing), we arrive at the Gibbs free energy of the mixture. The Gibbs free energy results indicate that the CdTe and CdSe mixtures exhibit phase separation. The upper consolute temperature is found to be 335 K. Finally, we provide the surface energy as a function of composition. Moreover, it roughly follows ideal solution theory, but with a negative deviation (negative excess surface energy). This indicates that alloying increases the stability, even for nano-particles.},
doi = {10.1080/08927022.2015.1007051},
journal = {Molecular Simulation},
number = 1,
volume = 42,
place = {United States},
year = {Fri Feb 20 00:00:00 EST 2015},
month = {Fri Feb 20 00:00:00 EST 2015}
}
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