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Related papers: Superconductivity in Co-doped LaFeAsO

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Using angle-resolved photoemission spectroscopy, we studied the electronic structure of NaFe$_{1-x}$Co$_x$As from an optimally doped superconducting compound ($x=0.028$) to a heavily overdoped non-superconducting one ($x=0.109$). Similar to…

Superconductivity · Physics 2012-06-21 S. T. Cui , S. Y. Zhu , A. F. Wang , S. Kong , S. L. Ju , X. G. Luo , X. H. Chen , G. B. Zhang , Z. Sun

The magnetic phase diagram has been mapped out via the measurements of electronic resistivity, magnetization and specific heat in the cobalt-based layered LnCo1-xFexAsO (Ln=La, Sm) compounds. The ferromagnetic (FM) transition at 63 K for…

Strongly Correlated Electrons · Physics 2013-01-14 Y. K. Li , X. F. Xu , C. Cao , C. Y. Shen , Y. K. Luo , Q. Tao , X. Lin , L. Zhang , G. H. Cao , Z. A. Xu

Study and comparison of over 30 examples of electron doped BaFe2As2 for transition metal (TM) = Co, Ni, Cu, and (Co/Cu mixtures) have lead to an understanding that the suppression of the structural/antiferromagnetic phase transition to low…

Superconductivity · Physics 2009-08-04 P. C. Canfield , S. L. Bud'ko , N. Ni , J. Q. Yan , A. Kracher

The nature and value of the order parameters (OPs) in the superconducting Fe-based oxypnictides REFeAsO_(1-x)F_x (RE = rare earth) are a matter of intense debate, also connected to the pairing mechanism which is probably unconventional.…

Superconductivity · Physics 2009-06-04 R. S. Gonnelli , D. Daghero , M. Tortello , G. A. Ummarino , V. A. Stepanov , J. S. Kim , R. K. Kremer

In this paper we report the synthesis of iron-based superconductors CaFe2-xRhxAs2 using one-step solid state reaction method, which crystallizes in the ThCr2Si2-type structure with a space group I4/mmm. The systematic evolution of the…

Superconductivity · Physics 2015-05-19 Yanpeng Qi , Lei Wang , Zhaoshun Gao , Dongliang Wang , Xianping Zhang , Chunlei Wang , Chao Yao , Yanwei Ma

By substituting the Fe with the 5d-transition metal Ir in SrFe2As2, we have successfully synthesized the superconductor SrFe2-xIrxAs2 with Tc = 22.3 K at x = 0.5. X-ray diffraction indicates that the material has formed the ThCr2Si2-type…

Superconductivity · Physics 2016-06-28 Fei Han , Xiyu Zhu , Ying Jia , Lei Fang , Peng Cheng , Huiqian Luo , Bing Shen , Hai-Hu Wen

The presence of macroscopic phase separation between the superconducting and magnetic phases in \cfcaf is demonstrated by muon spin rotation (muSR) measurements conducted across their phase boundaries (x=0.05-0.15). The magnetic phase tends…

Superconductivity · Physics 2009-07-13 S. Takeshita , R. Kadono , M. Hiraishi , M. Miyazaki , A. Koda , S. Matsuishi , H. Hosono

The electronic and magnetic properties of the new hydride superconductor CaFeAsH, which superconducts up to 47 K when electron-doped with La, and the isovalent alloy system CaFeAsH$_{1-x}$F$_x$ are investigated using density functional…

Strongly Correlated Electrons · Physics 2016-06-09 Y. N. Huang , D. Y. Liu , L. J. Zou , W. E. Pickett

Correlation between structural/microstructural and magneto-thermal transport properties of FeAs-based SmFeAsO and SmFeAsO0.85F0.15 has been studied in detail. The Rietveld analysis of room temperature powder X-ray diffraction (XRD) data…

Superconductivity · Physics 2013-09-26 Amit Srivastava , Anand Pal , Saurabh Singh , C. Shekhar , H. K. Singh , V. P. S. Awana , O. N. Srivastava

We report $^{75}$As nuclear magnetic resonance (NMR) / nuclear quadrupole resonance (NQR) and transmission electron microscopy (TEM) studies on LaFeAsO$_{1-x}$F$_{x}$. There are two superconducting domes in this material. The first one…

Superconductivity · Physics 2018-06-26 J. Yang , T. Oka , Z. Li , H. X. Yang , J. Q. Li , G. F. Chen , Guo-qing Zheng

Motivated by the discovery of superconductivity in F-doped LaFeAsO, we investigated the magnetic fluctuations in a related compound Fe(Se1-xTex)0.92 (x = 0.75, 1) using neutron scattering techniques. Non-superconducting FeTe0.92 shows…

Strongly Correlated Electrons · Physics 2015-05-13 Satoshi Iikubo , Masaki Fujita , Seiji Niitaka , Hidenori Takagi

Magnetization, susceptibility, specific heat, resistivity, neutron and x-ray diffraction have been used to characterize the properties of single crystalline CaFe2-xNixAs2 as a function of Ni doping for x varying from 0 to 0.1. The combined…

Since the discovery of copper oxide superconductor in 1986 [1], extensive efforts have been devoted to the search of new high-Tc superconducting materials, especially high-Tc systems other than cuprates. The recently discovered quaternary…

Superconductivity · Physics 2008-09-19 Zhi-An Ren , Jie Yang , Wei Lu , Wei Yi , Guang-Can Che , Xiao-Li Dong , Li-Ling Sun , Zhong-Xian Zhao

Electrical resistivity measurements under high pressures up to 29 GPa were performed for oxypnictide compound LaFeAsO. We found a pressure-induced superconductivity in LaFeAsO. The maximum value of Tc is 21 K at ~12 GPa. The pressure…

Superconductivity · Physics 2009-11-13 H. Okada , K. Igawa , H. Takahashi , Y. Kamihara , M. Hirano , H. Hosono , K. Matsubayashi , Y. Uwatoko

We investigated the recently found superconductor LaO_{1-x}F_xFeAs by X-ray absorption spectroscopy (XAS). From a comparison of the O K-edge with LDA calculations we find good agreement and are able to explain the structure and changes of…

The Phase diagram of SmFeAsO1-xFx in terms of x is exhibited in this study. SmFeAsO1-xFx from x = 0 to x = 0.3 were prepared by low temperature sintering with slow cooling. The low temperature sintering suppresses the formation of the…

[(Li0.8Fe0.2)OH]FeS and the series [(Li0.8Fe0.2)OH]Fe(S1-xSex) (0<x<1) were synthesized by hydrothermal methods and characterized by X-ray single crystal and powder diffraction, EDX and chemical analysis. Selenium-rich compounds show the…

Superconductivity · Physics 2015-03-04 Ursula Pachmayr , Dirk Johrendt

Superconductivity was achieved in PrFeAsO by partially substituting Pr^{3+} with Sr^{2+}. The electrical transport properties and structure of this new superconductor Pr_{1-x}Sr_xFeAsO at different doping levels (x = 0.05$\sim$ 0.25) were…

Superconductivity · Physics 2009-03-24 Gang Mu , Bin Zeng , Xiyu Zhu , Fei Han , Peng Cheng , Bing Shen , Hai-Hu Wen

We report a systematic investigation of Ba[Fe(1-x)Co(x)]2As2 based on transport and 75-As NMR measurements, and establish the electronic phase diagram. We demonstrate that doping progressively suppresses the uniform spin susceptibility and…

Superconductivity · Physics 2009-01-14 F. L. Ning , K. Ahilan , T. Imai , A. S. Sefat , R. Jin , M. A. McGuire , B. C. Sales , D. Mandrus

The recently discovered quaternary arsenide oxide superconductor La[O1-xFx]FeAs with the superconducting critical transition temperature (Tc) of 26 K [1], has been quickly expanded to another high-Tc superconducting system beyond copper…