Influence of magnetism on phonons in CaFe{sub 2}As{sub 2} as seen via inelastic x-ray scattering.

Journal Article · Thu Jan 01 00:00:00 EST 2009 · Phys. Rev. B

DOI:https://doi.org/10.1103/PhysRevB.79.220511· OSTI ID:961730

Hahn, S E; Lee, Y; Ni, N; Canfield, P C; Goldman, A I; McQueeney, R J; Harmon, B N; Alatas, A; Leu, B M; Alp, E E; Chung, D Y; Todorov, I S; Kanatzidis, M G

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 CaFe{sub 2}As{sub 2} 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.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC02-06CH11357
• OSTI ID: 961730
• Report Number(s): ANL/MSD/JA-64741; TRN: US0904308
• Journal Information: Phys. Rev. B, Vol. 79, Issue 2009; ISSN 1098-0121
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ARSENIC
IRON
MAGNETIC MOMENTS
MAGNETISM
PHONONS
PNICTIDES
SCATTERING
SENSITIVITY