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Ramasimha Varma A, Paul S, Itale A, Pable P, Tibrewala R, Dodal S, Yerunkar H, Bhaumik S, Shah V, Gururajan MP, Prasanna TRS. Electron-Phonon Interaction Contribution to the Total Energy of Group IV Semiconductor Polymorphs: Evaluation and Implications. ACS OMEGA 2023; 8:11251-11260. [PMID: 37008080 PMCID: PMC10061527 DOI: 10.1021/acsomega.2c08244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 02/28/2023] [Indexed: 06/19/2023]
Abstract
In density functional theory (DFT)-based total energy studies, the van der Waals (vdW) and zero-point vibrational energy (ZPVE) correction terms are included to obtain energy differences between polymorphs. We propose and compute a new correction term to the total energy, due to electron-phonon interactions (EPI). We rely on Allen's general formalism, which goes beyond the quasi-harmonic approximation (QHA), to include the free energy contributions due to quasiparticle interactions. We show that, for semiconductors and insulators, the EPI contributions to the free energies of electrons and phonons are the corresponding zero-point energy contributions. Using an approximate version of Allen's formalism in combination with the Allen-Heine theory for EPI corrections, we calculate the zero-point EPI corrections to the total energy for cubic and hexagonal polytypes of carbon, silicon and silicon carbide. The EPI corrections alter the energy differences between polytypes. In SiC polytypes, the EPI correction term is more sensitive to crystal structure than the vdW and ZPVE terms and is thus essential in determining their energy differences. It clearly establishes that the cubic SiC-3C is metastable and hexagonal SiC-4H is the stable polytype. Our results are consistent with the experimental results of Kleykamp. Our study enables the inclusion of EPI corrections as a separate term in the free energy expression. This opens the way to go beyond the QHA by including the contribution of EPI on all thermodynamic properties.
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Affiliation(s)
- Arjun
Varma Ramasimha Varma
- Department
of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Shilpa Paul
- Department
of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Anup Itale
- Department
of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Pranav Pable
- Department
of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Radhika Tibrewala
- Department
of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Samruddhi Dodal
- Department
of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Harshal Yerunkar
- Department
of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Saurav Bhaumik
- Department
of Mathematics, Indian Institute of Technology
Bombay, Mumbai 400076, India
| | - Vaishali Shah
- Department
of Scientific Computing, Modeling and Simulation, Savitribai Phule Pune University, Pune 411007, India
| | | | - Tiramkudlu R. S. Prasanna
- Department
of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, India
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Phonon softening and metallization of a narrow-gap semiconductor by thermal disorder. Proc Natl Acad Sci U S A 2011. [DOI: 10.1073/pnas.1014869108] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Ozolins V. First-principles calculations of free energies of unstable phases: the case of fcc W. PHYSICAL REVIEW LETTERS 2009; 102:065702. [PMID: 19257605 DOI: 10.1103/physrevlett.102.065702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Revised: 11/25/2008] [Indexed: 05/27/2023]
Abstract
Ab initio molecular dynamics simulations are used to solve the long-standing problem of calculating the free energies of unstable phases, such as fcc W. We find that fcc W is mechanically unstable with respect to long-wavelength shear at all temperatures considered (T>2500 K), while the short-wavelength phonon modes are anharmonically stabilized. The calculated fcc-bcc enthalpy and entropy differences at T=3500 K (308 meV and 0.74k_{B} per atom, respectively) agree well with the recent values derived from analysis of experimental data.
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Affiliation(s)
- V Ozolins
- Department of Materials Science and Engineering, University of California, Los Angeles, California, 90095-1595, USA
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Delaire O, Lucas MS, Muñoz JA, Kresch M, Fultz B. Adiabatic electron-phonon interaction and high-temperature thermodynamics of A15 compounds. PHYSICAL REVIEW LETTERS 2008; 101:105504. [PMID: 18851226 DOI: 10.1103/physrevlett.101.105504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Indexed: 05/26/2023]
Abstract
Inelastic neutron scattering was used to measure the phonon densities of states of the A15 compounds V3Si, V3Ge, and V3Co at temperatures from 10 to 1,273 K. It was found that phonons in V3Si and V3Ge, which are superconducting at low temperatures, exhibit an anomalous stiffening with increasing temperature, whereas phonons in V3Co have a normal softening behavior. First-principles calculations show that this anomalous increase in phonon frequencies at high temperatures originates with an adiabatic electron-phonon coupling mechanism. The anomaly is caused by the thermally induced broadening of sharp peaks in the electronic density of states of V3Si and V3Ge, which tends to decrease the electronic density at the Fermi level. These results show that the adiabatic electron-phonon coupling can influence the phonon thermodynamics at temperatures exceeding 1,000 K.
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Affiliation(s)
- O Delaire
- W. M. Keck Laboratory, California Institute of Technology, Mail stop 138-78, Pasadena, California 91125, USA
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Affiliation(s)
- Philip B. Allen
- a Department of Physics , State University of New York at Stony Brook , Stony Brook , New York , 11794-3800 , USA
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