Abstract
In the iron pnictides, the strong sensitivity of the iron magnetic moment to the arsenic position suggests a significant relationship between phonons and magnetism. We measured the phonon dispersion of several branches in the high-temperature tetragonal phase of CaFe2 As2 using inelastic x-ray scattering on single-crystal samples. These measurements were compared to ab initio calculations of the phonons. Spin-polarized calculations imposing the antiferromagnetic order present in the low-temperature orthorhombic phase dramatically improve agreement between theory and experiment. This is discussed in terms of the strong antiferromagnetic correlations that are known to persist in the tetragonal phase.
Original language | English |
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Article number | 220511 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 79 |
Issue number | 22 |
DOIs | |
State | Published - Jun 19 2009 |
Externally published | Yes |