J. Phys. Soc. Jpn. 77, pp. 47-53 (2008) [7 Pages]
Proceedings of the International Symposium on Fe-Pnictide Superconductors

NMR Measurements of Intrinsic Spin Susceptibility in LaFeAsO0.9F0.1

+ Affiliations
1Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S4M1, Canada2Canadian Institute for Advanced Research, Toronto, Ontario M5G1Z8, Canada3Materials Science and Technology Division, Oak Ridge National Laboratory, TN 37831, U.S.A.

We will probe the intrinsic behavior of spin susceptibility χ spin in the LaFeAsO 1- x F x superconductor ( x ∼0.1, T c ∼27 K) using 19 F and 75 As NMR techniques. Our new results firmly establish a pseudo-gap behavior with Δ PG / k B ∼140 K. The estimated magnitude of χ spin at 290 K, χ spin ∼1.8 ×10 -4 emu/mol-Fe, is approximately twice larger than that in high T c cuprates. We also show that χ spin levels off below ∼50 K down to T c .

©2008 The Physical Society of Japan


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