Superconductivity in Fluorine-Arsenide Sr1-xNdxFeAsF
We have successfully prepared the new family of fluoride-arsenide Sr1-xNdxFeAsF (0 ≤ x ≤ 0.5), and investigated the electrical and magnetic properties. Sr1-xNdxFeAsF with x = 0.4 and 0.5 show superconductivity, and their superconducting transition temperatures are 32 and 49 K, respectively. The superconducting volume fractions of Sr0.6Nd0.4FeAsF and Sr0.5Nd0.5FeAsF are ~11 and ~ 17 %, respectively. On the other hand, the sample of Sr1-xNdxFeAsF (0 ≤ x ≤ 0.35) is not superconducting but shows a metallic conductivity. All compounds show a weak ferromagnetism with the Curie temperature of above room temperature. The origin of the ferromagnetism may be due to the tiny Fe impurity.
J.-L. Bobet, B. Chevalier and D. Fruchart
R. Suganuma et al., "Superconductivity in Fluorine-Arsenide Sr1-xNdxFeAsF", Solid State Phenomena, Vol. 170, pp. 87-91, 2011