Temperature-dependent Local Structure of LaFeAsO(1-x)F(x): Probing the Atomic Correlations
The local structure of the parent and doped LaFeAsO{sub 1-x}F{sub x} (pnictide) compounds were studied by x-ray absorption spectroscopy and density functional methods. In the doped system, the Fe-As and Fe-Fe correlations are both well modeled by an Einstein model. For the Fe-As bonds, the Einstein temperatures are identical for the doped (11%) and undoped samples but the doped sample is found to have a lower level of static disorder. Doping is found to increases the effective Einstein temperature of Fe-Fe atomic correlation. The results suggest that the onset of superconductivity in the F doped system may be related to enhanced magnetic interactions. Density functional calculations of the total charge density reveal strong bonding between neighboring As ions but metal-like behavior in the Fe layers. It is also seen directly that the replacement of oxygen by fluorine modifies the electron charge density mainly on the Fe sites.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE SC OFFICE OF SCIENCE (SC)
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1041853
- Report Number(s):
- BNL-97531-2012-JA; JAPIAU; TRN: US201212%%265
- Journal Information:
- Journal of Applied Physics, Vol. 108, Issue 12; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
ABSORPTION SPECTRA
ABSORPTION SPECTROSCOPY
BONDING
CHARGE DENSITY
CRYSTAL STRUCTURE
DENSITY FUNCTIONAL METHOD
ELECTRON DENSITY
ELECTRONS
FERROMAGNETIC MATERIALS
FLUORINE
FUNCTIONALS
IRON COMPOUNDS
LANTHANUM COMPOUNDS
OXYGEN
SUPERCONDUCTIVITY
SUPERCONDUCTORS