Raman scattering near the structural phase transition of As2O5: order parameter treatment
- 20 August 1986
- journal article
- Published by IOP Publishing in Journal of Physics C: Solid State Physics
- Vol. 19 (23), 4537-4545
- https://doi.org/10.1088/0022-3719/19/23/017
Abstract
The structural phase transition of As2O5 at Tc=578K is associated with frequency shifts of the strongest Raman lines at 35.5, 66.2, 567.7 and 579 cm-1 according to omega approximately ((T-Tc)/Tc)0.5. Although the temperature evolution of the line profiles is grossly in agreement with a displacive transition mechanism, the saturation of the lowest phonon branch at 27 cm-1 and the spontaneous increase of the linewidth at Tc by 1.2 cm-1 indicate the influence of relaxational or order-disorder processes. The temperature dependence of the order parameter related to the sublattice deformation follows mean-field theory within experimental resolution. The possible influence of order parameter coupling on the structural phase transition is discussed.Keywords
This publication has 20 references indexed in Scilit:
- Effect of strain-induced order-parameter coupling on the ferroelastic behaviour of lead phosohate-arsenatePhase Transitions, 1986
- Phase transition in K2Cd2(SO4)3: investigation of the non-linear dependence of spontaneous strain and morphic birefringence on order parameter as determined from excess entropy measurementsJournal of Physics C: Solid State Physics, 1984
- Schwingungsspektroskopische Untersuchungen an As2O5 und AsSbO5Zeitschrift für anorganische und allgemeine Chemie, 1983
- Precursor order and Raman scattering near displacive phase transitionsJournal of Physics C: Solid State Physics, 1980
- How accurate was the carat?Nature, 1979
- Die Kristallstruktur von As2O5, eine neue RaumnetzstrukturZeitschrift für anorganische und allgemeine Chemie, 1978
- Defects and the central peak near structural phase transitionsPhysical Review B, 1976
- Symmetry classification and properties of equi-translation structural phase transitionsCzechoslovak Journal of Physics, 1975
- Structural Phase Transitions in LangbeinitesPhysica Status Solidi (b), 1972
- Determination of the State Parameters and Formulation of Spontaneous Strain for FerroelasticsJournal of the Physics Society Japan, 1970