We report on the synthesis and structural/ microstructural studies of iron based fluorine doped LaOFeAs superconductors. We have successfully synthesized fluorine doped superconducting LaO1-xFxFeAs materials by choosing lower temperature (1150^0C) and longer synthesis duration (60 hours) as compared to the standard values of these employed in the pioneering first contribution [Kamihara et al 2008 J Am Chem Soc 130 3296]. Decrease of lattice parameters as determined by x-ray diffraction confirm the substitution of fluorine. The superconducting transition temperature is 27.5 K which is observed at doping level of x=0.2. This superconducting material LaO1-xFxFeAs exhibits interesting microstructural characteristic. This relates to the existence of another structural phase, besides the standard phase, having c parameters of ~12.67A. This suggests existence of modulated structure, similar to the cuprates, in these new oxypnictides. This phase may have new impacts on this new high-Tc family.
@article{arxiv.0811.0094,
title = {Synthesis and Microstructural Studies of Iron Oxypnictide LaO1-xFxFeAs Superconductors},
author = {Chandra Shekhar and Sonal Singh and P K Siwach and H K Singh and O N Srivastava},
journal= {arXiv preprint arXiv:0811.0094},
year = {2008}
}
Comments
5 pages, 5 figures. Accepted in Supercod. Sci Technol (2008)