Spatial Inhomogeneity in RFeAsO1-xFx (R =Pr, Nd) Determined from Rare Earth Crystal Field Excitations

Abstract

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 non-magnetic and magnetic ground states, respectively, indicating that the enhancement of Tc compared to LaFeAsO1-xFx is not due to rare earth magnetism.

arXiv comment4 pages 4 figures

References in corpus (17)

• Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO${}_{1-x}$F${}_x$FeAs
• Superconductivity in iron-based F-doped layered quaternary compound Nd[O1-xFx]FeAs
• Superconductivity at 25 K in hole doped $(L{a}_{1-x}S{r}_x)OFeAs$
• Superconductivity at 52 K in iron-based F-doped layered quaternary compound Pr[O1-xFx]FeAs
• Competing order and nature of the pairing state in the iron pnictides
• Electronic phase separation in the slightly underdoped iron pnictide superconductor Ba(1-x)K(x)Fe(2)As(2)
• Where Are the Extra d Electrons in Transition-Metal Substituted Fe Pnictides?
• Lattice and Magnetic structures of PrFeAsO, PrFeAsO0.85F0.15 and PrFeAsO0.85
• Interplay of Rare Earth and Iron magnetism in RFeAsO with R = La, Ce, Pr, and Sm: A muon spin relaxation study and symmetry analysis
• Influence of the rare-earth element on the effects of the structural and magnetic phase transitions in CeFeAsO, PrFeAsO, and NdFeAsO
• Magnetic Ordering and Negative Thermal Expansion in PrFeAsO
• Nanoscale electronic order in iron pnictides
• Phase diagram of the PrFeAsO${}_{1-x}$F${}_x$ superconductor
• Interplay between Fe and Nd magnetism in NdFeAsO single crystals
• Magnetic and Superconducting Properties of FeAs-based High-Tc Superconductors with Gd
• Coupling between 4f and itinerant electrons in SmFeAsO1-xFx (0.15 < x < 0.2) superconductors: an NMR study
• Superconductivity and Magnetism in REFeAsO1-xFx (RE=Rare Earth Elements)

Cited by in corpus (7)

• The magnetic and electronic properties of Oxyselenides - influence of transition metal ions and lanthanides
• Separation of antiferromagnetism and high-temperature superconductivity in Ca${}_{1-x}$La${}_x$Fe${}_2$As${}_2$ under pressure
• Local lattice distortions vs. structural phase transition in NdFeAsO1-xFx
• Pr magnetism and its interplay with the Fe spin density wave in PrFeAsO
• Inelastic neutron scattering study of crystal field excitations of Nd3+ in NdFeAsO
• Crystal field excitations and magnons: their roles in oxyselenides Pr2O2M2OSe2 (M = Mn, Fe)
• Improvement in granularity of NdFeAsO0.8F0.2 superconductor through Ag doping