TY  - JOUR
AU  - Goremychkin, E.A.
AU  - Osborn, R.
AU  - Wang, C.H.
AU  - Lumsden, M.D.
AU  - McGuire, M.A.
AU  - Sefat, A.S.
AU  - Sales, B.C.
AU  - Mandrus, D.
AU  - Ronnow, H.M.
AU  - Su, Y.
AU  - Christianson, A.D.
TI  - Spatial inhomogeneity in RFeAsO(1-x)F(x) (R = Pr, Nd) determined from rare-earth crystal-field excitations
JO  - Physical review / B
VL  - 83
IS  - 21
SN  - 1098-0121
CY  - College Park, Md.
PB  - APS
M1  - PreJuSER-15731
SP  - 212505
PY  - 2011
N1  - We acknowledge useful discussions with E. Dagotto and assistance in the neutron-scattering experiments from O. Garlea (ORNL), T. Guidi (ISIS), A. Orecchini (ILL), and M. Koza (ILL). Research at Argonne and Oak Ridge is supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division and Scientific User Facilities Division (Argonne Contract No. DE-AC02-06CH11357).
AB  - We report inelastic neutron-scattering measurements of crystal-field transitions in PrFeAsO, PrFeAsO0.87F0.13, and NdFeAsO0.85F0.15. Doping with fluorine produces additional crystal-field excitations, providing evidence that there are two distinct charge environments around the rare-earth ions, with probabilities that are consistent with a random distribution of dopants on the oxygen sites. The 4f electrons of the Pr3+ and Nd3+ ions have nonmagnetic and magnetic ground states, respectively, indicating that the enhancement of T-c compared to LaFeAsO1-xFx is not due to rare-earth magnetism.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000292127500001
DO  - DOI:10.1103/PhysRevB.83.212505
UR  - https://juser.fz-juelich.de/record/15731
ER  -