Abstract
We report inelastic neutron-scattering measurements of crystal-field transitions in PrFeAsO, PrFeAsO0.87F0.13, and NdFeAsO 0.85F0.15. 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 Tc compared to LaFeAsO1-xFx is not due to rare-earth magnetism.
Original language | English |
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Article number | 212505 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 83 |
Issue number | 21 |
DOIs | |
State | Published - Jun 27 2011 |