By investigating the F-doping effect in the SmFeAsO1−xFx, SmFeAsO1−xF0.20 and

SmFeAsO0.90Fx systems, as well as the oxygen vacancy effect in SmFeAsO1−y

superconductors, it was found that the substitution range of F for oxygen in the

SmFeAsO1−xFx system prepared via the ambient pressure method was 0 ≤ x ≤

0.125, that F could not substitute for oxygen in samples without oxygen vacancies,

that the oxygen-deficient SmFeAsO1−y superconductor could not be prepared by the

ambient pressure method and that F-doping and oxygen vacancies both led to

lattice shrinkage. Oxygen-deficient SmFeAsO0.85 and F-doped SmFeAsO0.85F0.15,

prepared using the high-pressure method, exhibited higher superconducting

transition temperature when compared to SmFeAsO0.85F0.15 prepared using the

ambient pressure method.

The Role of F-Doping and Oxygen Vacancies on the Superconductivity in

SmFeAsO Compounds. J.Yang, Z.A.Ren, G.C.Che, W.Lu, X.L.Shen, Z.C.Li,

W.Yi, X.L.Dong, L.L.Sun, F.Zhou, Z.X.Zhao: Superconductor Science and

Technology, 2009, 22[2], 025004