2008/06/10 by Gang Wu, G. Wu, H. Chen +14 · 31 citations
Business, Management and Accounting · Chemistry · Materials Science · Physics and Astronomy · #Analytical Chemistry (journal) #Annealing (glass) #Chemistry #Condensed matter physics #Corporate Taxation and Avoidance #Doping #Intellectual Capital and Performance Analysis #Iron-based superconductors research #Materials science #Metallurgy #Oxygen #Oxygen deficiency #Physics #Superconductivity #cond-mat.mtrl-sci #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.78.092503
published in Physical Review B 78(9) (American Physical Society) · 4 pages, 4 figures
arxiv created 2008/06/10 · openalex publication_date 2008/09/16 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We synthesized single phase La0.85Sr0.15FeAsO_1\ensuremath-\ensuremathδ samples and systematically studied the effect of oxygen deficiency in this system. It is found that partial substitution of Sr for La induces the hole carrier evidenced by positive thermoelectric power (TEP) but no bulk superconductivity is observed. The superconductivity can be realized by annealing the as-grown sample in vacuum to produce the oxygen deficiency. With increasing oxygen deficiency, the superconducting transition temperature (Tc) increases and the maximum Tc reaches 26 K---the same as that observed in the LaFeAsO_1\ensuremath-xFx system. TEP changes the sign from positive for the nonsuperconducting as-grown sample to negative for the superconducting samples with oxygen deficiency, while RH keeps negative for all samples. It suggests that the dominated carrier in La0.85Sr0.15FeAsO_1\ensuremath-\ensuremathδ is electronlike.