Vibrational contributions to phase stability in the Mo-Ru system

Sean H. Kessler; David G. Abrecht; Richard A. Clark; Jon M. Schwantes

doi:10.1016/j.jallcom.2016.08.071

Vibrational contributions to phase stability in the Mo-Ru system

Sean H. Kessler, David G. Abrecht, Richard A. Clark, Jon M. Schwantes

Mechanical Engineering

Research output: Contribution to journal › Article › peer-review

5 Scopus citations

Abstract

Density functional theory using the Perdew-Burke-Ernzerhof functional and the small displacement method was used to calculate the quasiharmonic phonon density of states (DOS) for 69 ordered structures in the Mo-Ru substitutional alloy system to estimate the effect of vibrational contributions to the free energy of formation. These structures were used to determine interaction parameters in the cluster expansion approximation up to triplet sets to incorporate the vibrational contribution into the configurational energy of formation for the randomly mixed system. The free energies calculated using this approximation are shown to resolve lingering disagreement between reported theoretical and experimental results, and the stabilizing effect of vibrational entropy is observed to improve theoretical predictions of the Mo-Ru phase diagram.

Original language	English (US)
Pages (from-to)	969-976
Number of pages	8
Journal	Journal of Alloys and Compounds
Volume	689
DOIs	https://doi.org/10.1016/j.jallcom.2016.08.071
State	Published - 2016

All Science Journal Classification (ASJC) codes

Mechanics of Materials
Mechanical Engineering
Metals and Alloys
Materials Chemistry

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10.1016/j.jallcom.2016.08.071

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@article{1832be7e88ac420ebd26f91040d34023,

title = "Vibrational contributions to phase stability in the Mo-Ru system",

abstract = "Density functional theory using the Perdew-Burke-Ernzerhof functional and the small displacement method was used to calculate the quasiharmonic phonon density of states (DOS) for 69 ordered structures in the Mo-Ru substitutional alloy system to estimate the effect of vibrational contributions to the free energy of formation. These structures were used to determine interaction parameters in the cluster expansion approximation up to triplet sets to incorporate the vibrational contribution into the configurational energy of formation for the randomly mixed system. The free energies calculated using this approximation are shown to resolve lingering disagreement between reported theoretical and experimental results, and the stabilizing effect of vibrational entropy is observed to improve theoretical predictions of the Mo-Ru phase diagram.",

author = "Kessler, {Sean H.} and Abrecht, {David G.} and Clark, {Richard A.} and Schwantes, {Jon M.}",

note = "Funding Information: This work was funded by Pacific Northwest National Laboratory utilizing Laboratory Directed Research and Development (LDRD) funds with support from the Nuclear Process Science Initiative (NPSI) and was performed using PNNL Institutional Computing (PIC). Pacific Northwest National Laboratory is operated by Battelle Memorial Institute for the United States Department of Energy under contract DE-AC06-76RLO-1830 . Publisher Copyright: {\textcopyright} 2016 Elsevier B.V.",

year = "2016",

doi = "10.1016/j.jallcom.2016.08.071",

language = "English (US)",

volume = "689",

pages = "969--976",

journal = "Journal of Alloys and Compounds",

issn = "0925-8388",

publisher = "Elsevier B.V.",

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TY - JOUR

T1 - Vibrational contributions to phase stability in the Mo-Ru system

AU - Kessler, Sean H.

AU - Abrecht, David G.

AU - Clark, Richard A.

AU - Schwantes, Jon M.

N1 - Funding Information: This work was funded by Pacific Northwest National Laboratory utilizing Laboratory Directed Research and Development (LDRD) funds with support from the Nuclear Process Science Initiative (NPSI) and was performed using PNNL Institutional Computing (PIC). Pacific Northwest National Laboratory is operated by Battelle Memorial Institute for the United States Department of Energy under contract DE-AC06-76RLO-1830 . Publisher Copyright: © 2016 Elsevier B.V.

PY - 2016

Y1 - 2016

N2 - Density functional theory using the Perdew-Burke-Ernzerhof functional and the small displacement method was used to calculate the quasiharmonic phonon density of states (DOS) for 69 ordered structures in the Mo-Ru substitutional alloy system to estimate the effect of vibrational contributions to the free energy of formation. These structures were used to determine interaction parameters in the cluster expansion approximation up to triplet sets to incorporate the vibrational contribution into the configurational energy of formation for the randomly mixed system. The free energies calculated using this approximation are shown to resolve lingering disagreement between reported theoretical and experimental results, and the stabilizing effect of vibrational entropy is observed to improve theoretical predictions of the Mo-Ru phase diagram.

AB - Density functional theory using the Perdew-Burke-Ernzerhof functional and the small displacement method was used to calculate the quasiharmonic phonon density of states (DOS) for 69 ordered structures in the Mo-Ru substitutional alloy system to estimate the effect of vibrational contributions to the free energy of formation. These structures were used to determine interaction parameters in the cluster expansion approximation up to triplet sets to incorporate the vibrational contribution into the configurational energy of formation for the randomly mixed system. The free energies calculated using this approximation are shown to resolve lingering disagreement between reported theoretical and experimental results, and the stabilizing effect of vibrational entropy is observed to improve theoretical predictions of the Mo-Ru phase diagram.

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DO - 10.1016/j.jallcom.2016.08.071

M3 - Article

AN - SCOPUS:84982204110

SN - 0925-8388

VL - 689

SP - 969

EP - 976

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

ER -

Vibrational contributions to phase stability in the Mo-Ru system

Abstract

All Science Journal Classification (ASJC) codes

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