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Phonon softening near structural transition in BaFe2As2 observed by inelastic x-ray scattering
- Source :
- Physical Review B 84, 224305 (2011)
- Publication Year :
- 2011
-
Abstract
- In this work we present the results of an inelastic x-ray scattering experiment detailing the behavior of the transverse acoustic [110] phonon in BaFe2As2 as a function of temperature. When cooling through the structural transition temperature, the transverse acoustic phonon energy is reduced from the value at room temperature, reaching a maximum shift near inelastic momentum transfer q=0.1. This softening of the lattice results in a change of the symmetry from tetragonal to orthorhombic at the same temperature as the transition to long-range antiferromagnetic order. While the lattice distortion is minor, the anisotropy in the magnetic exchange constants in pnictide parent compounds is large. We suggest mechanisms of electron-phonon coupling to describe the interaction between the lattice softening and onset of magnetic ordering.<br />Comment: As accepted for publication in Physical Review B
Details
- Database :
- arXiv
- Journal :
- Physical Review B 84, 224305 (2011)
- Publication Type :
- Report
- Accession number :
- edsarx.1112.0261
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevB.84.224305