Local structure of NdFeAsO 1 - xF x (x = 0.0, 0.05, 0.15 and 0.18) high temperature iron-pnictide superconductor system is studied using arsenic K-edge extended x-ray absorption fine structure measurements as a function of temperature. Fe-As bond length shows only a weak temperature and F-substitution dependence, consistent with the strong covalent nature of this bond. The temperature dependence of the mean square relative displacements of the Fe-As bond length are well described by the correlated Einstein model for all the samples, but with different Einstein temperatures for the superconducting and non-superconducting samples. The results indicate distinct local Fe-As lattice dynamics in the superconducting and non-superconducting iron-pnictide systems. © 2011 IOP Publishing Ltd.
Temperature-dependent local structure of NdFeAsO 1 - XF x system using arsenic K-edge extended x-ray absorption fine structure / B., Joseph; Iadecola, Antonella; L., Malavasi; Saini, Naurang Lal. - In: JOURNAL OF PHYSICS. CONDENSED MATTER. - ISSN 0953-8984. - 23:26(2011), p. 265701. [10.1088/0953-8984/23/26/265701]
Temperature-dependent local structure of NdFeAsO 1 - XF x system using arsenic K-edge extended x-ray absorption fine structure
IADECOLA, ANTONELLA;SAINI, Naurang Lal
2011
Abstract
Local structure of NdFeAsO 1 - xF x (x = 0.0, 0.05, 0.15 and 0.18) high temperature iron-pnictide superconductor system is studied using arsenic K-edge extended x-ray absorption fine structure measurements as a function of temperature. Fe-As bond length shows only a weak temperature and F-substitution dependence, consistent with the strong covalent nature of this bond. The temperature dependence of the mean square relative displacements of the Fe-As bond length are well described by the correlated Einstein model for all the samples, but with different Einstein temperatures for the superconducting and non-superconducting samples. The results indicate distinct local Fe-As lattice dynamics in the superconducting and non-superconducting iron-pnictide systems. © 2011 IOP Publishing Ltd.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.