This title appears in the Scientific Report :
2010
Please use the identifier:
http://dx.doi.org/10.1103/PhysRevB.82.104301 in citations.
Please use the identifier: http://hdl.handle.net/2128/10967 in citations.
Lattice dynamics of rhenium trioxide from the quasiharmonic approximation
Lattice dynamics of rhenium trioxide from the quasiharmonic approximation
The quasiharmonic theory is applied to study the lattice dynamics and thermal properties of rhenium trioxide, a material exhibiting the negative thermal-expansion phenomenon. Phonons are calculated at several external pressures. The pressure dependence of the M, R, and zone-center phonon modes is an...
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Personal Name(s): | Wdowik, U.D. |
---|---|
Parlinski, K. / Chatterji, T. / Rols, S. / Schober, H. | |
Contributing Institute: |
JCNS; JCNS Streumethoden; IFF-4 Neutronenstreuung; IFF-5 |
Published in: | Physical Review B Physical review / B, 82 82 (2010 2010) 10 10, S. 104301 104301 |
Imprint: |
College Park, Md.
APS
2010
|
Physical Description: |
104301 |
DOI: |
10.1103/PhysRevB.82.104301 |
Document Type: |
Journal Article |
Research Program: |
Großgeräte für die Forschung mit Photonen, Neutronen und Ionen (PNI) BioSoft: Makromolekulare Systeme und biologische Informationsverarbeitung |
Series Title: |
Physical Review B
82 |
Subject (ZB): | |
Link: |
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Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/10967 in citations.
The quasiharmonic theory is applied to study the lattice dynamics and thermal properties of rhenium trioxide, a material exhibiting the negative thermal-expansion phenomenon. Phonons are calculated at several external pressures. The pressure dependence of the M, R, and zone-center phonon modes is analyzed. Relying on the Gruneisen formalism an influence of temperature on the M phonon mode is investigated. The calculated free energy of the system provides predictions for the temperature dependence of such quantities as equilibrium volume and crystal thermal expansivity. The mean-squared vibrations of rhenium-trioxide atoms are investigated versus temperature and pressure. Results of the calculations indicate a softening of the M and R phonons with pressure and a large negative Gruneisen constants for these modes. A decrease in the crystal volume is observed up to 170 K. The thermal-expansion coefficient shows a minimum in the vicinity of 100 K which corresponds to a minimum of the anisotropy in the oxygen thermal vibrations perpendicular to the Re-O bond and along the bond. Anisotropy in the oxygen Debye-Waller factors follows from the anisotropy of the force constants at the oxygen site. Inelastic neutron-scattering measurements performed at room temperature are reported together with the generalized phonon densities of states. A comparison between present calculations and the experimental data as well as other theoretical studies is provided. |