%0 Journal Article
%A Wdowik, U.D.
%A Parlinski, K.
%A Chatterji, T.
%A Rols, S.
%A Schober, H.
%T Lattice dynamics of rhenium trioxide from the quasiharmonic approximation
%J Physical review / B
%V 82
%N 10
%@ 1098-0121
%C College Park, Md.
%I APS
%M PreJuSER-11953
%P 104301
%D 2010
%Z Interdisciplinary Modeling Center ICM, Warsaw University, Poland is acknowledged for providing the computer facilities to support part of the present calculations under Grant No. G28-12.
%X 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.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000281720100003
%R 10.1103/PhysRevB.82.104301
%U https://juser.fz-juelich.de/record/11953