The REFeAsO (RE =La, Pr, Nd and Sm) system has been studied by RE L 3 x-ray absorption near edge structure(XANES) spectroscopy to explore the contribution of the REO spacers between the electronically active FeAs slabs in these materials. The XANES spectra have been simulated by full multiple scattering calculations to describe the different experimental features and their evolution with the RE size. The near edge feature just above the L 3 white line is found to be sensitive to the ordering/disordering of oxygen atoms in the REO layers. In addition, shape resonance peaks due to As and O scattering change systematically, indicating local structural changes in the FeAs slabs and the REO spacers due to RE size. The results suggest that interlayer coupling and oxygen order/disorder in the REO spacers may have an important role in the superconductivity and itinerant magnetism of the oxypnictides. © IOP Publishing Ltd.
Local structural disorder in REFeAsO oxypnictides by RE L3 edge XANES / W., Xu; A., Marcelli; B., Joseph; Iadecola, Antonella; W. S., Chu; D., Di Gioacchino; Bianconi, Antonio; Z. Y., Wu; Saini, Naurang Lal. - In: JOURNAL OF PHYSICS. CONDENSED MATTER. - ISSN 0953-8984. - 22:12(2010), pp. 125701-1-125701-7. [10.1088/0953-8984/22/12/125701]
Local structural disorder in REFeAsO oxypnictides by RE L3 edge XANES
IADECOLA, ANTONELLA;BIANCONI, Antonio;SAINI, Naurang Lal
2010
Abstract
The REFeAsO (RE =La, Pr, Nd and Sm) system has been studied by RE L 3 x-ray absorption near edge structure(XANES) spectroscopy to explore the contribution of the REO spacers between the electronically active FeAs slabs in these materials. The XANES spectra have been simulated by full multiple scattering calculations to describe the different experimental features and their evolution with the RE size. The near edge feature just above the L 3 white line is found to be sensitive to the ordering/disordering of oxygen atoms in the REO layers. In addition, shape resonance peaks due to As and O scattering change systematically, indicating local structural changes in the FeAs slabs and the REO spacers due to RE size. The results suggest that interlayer coupling and oxygen order/disorder in the REO spacers may have an important role in the superconductivity and itinerant magnetism of the oxypnictides. © IOP Publishing Ltd.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
