| DOI | Resolve DOI: https://doi.org/10.1103/PhysRevB.74.054102 |
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| Author | Search for: Li, Yan; Search for: Zhang, Lijun; Search for: Cui, Tian; Search for: Ma, Yanming; Search for: Zou, Guangtian; Search for: Klug, Dennis1 |
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| Affiliation | - National Research Council of Canada. NRC Steacie Institute for Molecular Sciences
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| Format | Text, Article |
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| Subject | APW calculations; density functional theory; elastic constants; high-pressure solid-state phase transformations; phonons; shear modulus; silver compounds; soft modes |
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| Abstract | The phonons and elastic constants of rocksalt AgCl and AgBr under pressure are extensively studied by using the pseudopotential plane-wave method within density functional theory. A pressure-induced soft transverse acoustic (TA) phonon mode is identified for both compounds. Interestingly, each compound shows a different phonon softening behavior. A TA phonon branch softens to zero pressure at 6.5 GPa along [xi00] direction in AgCl, resulting in the phase transition from the rocksalt structure to the monoclinic structure. A softening TA phonon mode at the zone boundary X point in AgBr is predicted and the deduced transition pressure of ~9.8 GPa is found to be 24% larger than the experimental measurement of ~7.9 GPa. The predicted larger transition pressure indicated that the TA softening phonon mode at the zone boundary X point in AgBr may not independently induce the phase transition. Moreover, a pressure-induced softening of shear modulus in C44 is also verified for both compounds. However, it is suggested that the phonon instability, instead of C44 instability, dominates the pressure-induced structural phase transition. |
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| Publication date | 2006 |
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| Publisher | American Physical Society |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| NPARC number | 12326997 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | 85b9ec78-483f-4a2c-a3b7-52b789681a02 |
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| Record created | 2009-09-10 |
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| Record modified | 2023-06-23 |
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