Effect of Structural Parameters on Superconductivity in Fluorine-Free LnFeAsO1-y (Ln = La, Nd)
Abstract
The crystal structure of LnFeAsO1-y (Ln = La, Nd) has been studied by the powder neutron diffraction technique. The superconducting phase diagram of NdFeAsO1-y is established as a function of oxygen content which is determined by Rietveld refinement. The small As-Fe bond length suggests that As and Fe atoms are connected covalently. FeAs4-tetrahedrons transform toward a regular shape with increasing oxygen deficiency. Superconducting transition temperatures seem to attain maximum values for regular FeAs4-tetrahedrons.
- Publication:
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Journal of the Physical Society of Japan
- Pub Date:
- August 2008
- DOI:
- 10.1143/JPSJ.77.083704
- arXiv:
- arXiv:0806.3821
- Bibcode:
- 2008JPSJ...77h3704L
- Keywords:
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- Condensed Matter - Superconductivity
- E-Print:
- J. Phys. Soc. Jpn. 77 (2008) 083704