TY  - JOUR
AU  - Zbiri, M.
AU  - Mittal, R.
AU  - Rols, S.
AU  - Su, Y.
AU  - Xiao, Y.
AU  - Schober, H.
AU  - Chaplot, S.L.
AU  - Johnson, M.
AU  - Chatterji, T.
AU  - Inoue, Y.
AU  - Matsuishi, S.
AU  - Hosono, H.
AU  - Brückel, T.
TI  - Magnetic lattice dynamics of the oxygen-free FeAs pnictides: How sensitive are phonons to magnetic ordering?
JO  - Journal of physics / Condensed matter
VL  - 22
SN  - 0953-8984
CY  - Bristol
PB  - IOP Publ.
M1  - PreJuSER-11023
SP  - 315701
PY  - 2010
N1  - Record converted from VDB: 12.11.2012
AB  - To shed light on the role of magnetism on the superconducting mechanism of the oxygen-free FeAs pnictides, we investigate the effect of magnetic ordering on phonon dynamics in the low-temperature orthorhombic parent compounds, which present a spin density wave. The study covers both the 122 (AFe(2)As(2); A = Ca, Sr, Ba) and 1111 (AFeAsF; A = Ca, Sr) phases. We extend our recent work on the Ca (122 and 1111) and Ba (122) cases by treating, computationally and experimentally, the 122 and 1111 Sr compounds. The effect of magnetic ordering is investigated through detailed non-magnetic and magnetic lattice dynamical calculations. The comparison of the experimental and calculated phonon spectra shows that the magnetic interactions/ordering have to be included in order to reproduce well the measured density of states. This highlights a spin-correlated phonon behavior which is more pronounced than the apparently weak electron-phonon coupling estimated in these materials. Furthermore, there is no noticeable difference between phonon spectra of the 122 Ba and Sr, whereas there are substantial differences when comparing these to CaFe(2)As(2) originating from different aspects of structure and bonding.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:21399367
UR  - <Go to ISI:>//WOS:000279996400012
DO  - DOI:10.1088/0953-8984/22/31/315701
UR  - https://juser.fz-juelich.de/record/11023
ER  -