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Related papers: Superconductivity in Co-doped LaFeAsO

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By using solid state reaction method, we have synthesized the Pd-doped superconductor SrFe2-xPdxAs2. The systematic evolution of the lattice constants indicated that the Fe ions were successfully replaced by the Pd. By increasing the doping…

Superconductivity · Physics 2016-06-28 Xiyu Zhu , Fei Han Peng Cheng , Bing Shen , Hai-Hu Wen

The interplay between different ordered phases, such as superconducting, charge or spin ordered phases, is of central interest in condensed matter physics. The very recent discovery of superconductivity with a remarkable T$_c$= 26 K in…

Superconductivity · Physics 2008-06-30 J. Dong , H. J. Zhang , G. Xu , Z. Li , G. Li , W. Z. Hu , D. Wu , G. F. Chen , X. Dai , J. L. Luo , Z. Fang , N. L. Wang

We examined doping effect of 3d transition metal elements (TM: Cr, Mn, Co, Ni, and Cu) at the Fe site of a quaternary fluoroarsenide CaFeAsF, an analogue of 1111-type parent compound LaFeAsO. The anomaly at ~120 K observed in resistivity…

We have synthesized a quaternary fluoroarsenide SrFeAsF with the ZrCuSiAs-type structure (P4/nmm, a = 0.3999 and c = 0.8973 nm), which is composed of an alternately stacked (FeAs)- and (SrF)+ layers, analogous to the FeAs-based…

Superconductivity · Physics 2008-11-10 Satoru Matsuishi , Yasunori Inoue , Takatoshi Nomura , Masahiro Hirano , Hideo Hosono

We use neutron scattering to study the structural distortion and antiferromagnetic (AFM) order in LaFeAsO$_{1-x}$F$_{x}$ as the system is doped with fluorine (F) to induce superconductivity. In the undoped state, LaFeAsO exhibits a…

Superconductivity · Physics 2009-11-13 Q. Huang , Jun Zhao , J. W. Lynn , G. F. Chen , J. L. Luo , N. L. Wang , Pengcheng Dai

We report magnetic susceptibility, resistivity and heat capacity measurements on single crystals of the Sr(Fe1-xCox)2As2 and Sr1-yEuy(Fe0.88Co0.12)2As2 series. The optimal Co concentration for superconductivity in Sr(Fe1-xCox)2As2 is…

Superconductivity · Physics 2015-05-20 Rongwei Hu , Sergey L. Bud'ko , Warren E. Straszheim , Paul C. Canfield

We report on superconductivity in CeFeAs1-xPxO and the possible coexistence with Ce- ferromagnetism (FM) in a small homogeneity range around x = 30% with ordering temperatures of T_SC = T_C = 4K. The antiferromagnetic (AFM) ordering…

We report the synthesis and characterization of antimony doped oxypnictide superconductor, LaO0.8F0.2FeAs1-xSbx (x = 0.05 and 0.10). The parent compound LaOFeAs with fluorine doping exhibits superconductivity at maximum transition…

Superconductivity · Physics 2009-03-23 S. J. Singh , J. Prakash , S. Patnaik , A. K. Ganguli

Application of pressures or electron-doping through Co substitution into Fe sites transforms the itinerant antiferromagnet BaFe(2)As(2) into a superconductor with the Tc exceeding 20K. We carried out systematic transport measurements of…

Superconductivity · Physics 2009-11-13 K. Ahilan , J. Balasubramaniam , F. L. Ning , T. Imai , A. S. Sefat , R. Jin , M. A. McGuire , B. C. Sales , D. Mandrus

The phase diagram of NdFe1-xCoxAsO for low cobalt substitution consists of a superconducting dome (0.05 < x < 0.20) with a maximum critical temperature of 16.5(2) K for x = 0.12. The x = 1 end member, NdCoAsO, is an itinerant ferromagnet…

We report a strategy to induce superconductivity in the BiS$_2$-based compound LaOBiS$_2$. Instead of substituting F for O, we increase the charge-carrier density (electron dope) via substitution of tetravalent Th$^{+4}$, Hf$^{+4}$,…

Superconductivity · Physics 2013-05-22 D. Yazici , K. Huang , B. D. White , I. Jeon , V. W. Burnett , A. J. Friedman , I. K. Lum , M. Nallaiyan , S. Spagna , M. B. Maple

A new hight Tc Fe-based compound system, AFe2As2 with A = K, Cs, K/Sr and Cs/Sr has been found. Through electron-doping, Tc of the A = K and Cs compounds rises to ~37 K, and finally enter a spin-density-wave state (SDW) through further…

Superconductivity · Physics 2008-09-09 K. Sasmal , B. Lv , B. Lorenz , A. Guloy , F. Chen , Y. Xue , C. W. Chu

We report on the synthesis and structural/ microstructural studies of iron based fluorine doped LaOFeAs superconductors. We have successfully synthesized fluorine doped superconducting LaO1-xFxFeAs materials by choosing lower temperature…

Superconductivity · Physics 2008-11-29 Chandra Shekhar , Sonal Singh , P K Siwach , H K Singh , O N Srivastava

We argue that the newly discovered superconductivity in a nearly magnetic, Fe-based layered compound is unconventional and mediated by antiferromagnetic spin fluctuations, though different from the usual superexchange and specific to this…

Superconductivity · Physics 2015-05-13 I. I. Mazin , D. J. Singh , M. D. Johannes , M. H. Du

We measured the resistivity and magnetic susceptibility to map out the phase diagram of single crystalline NaFe$_{1-x}$Co$_x$As. Replacement of Fe by Co suppresses both the structural and magnetic transition, while enhances the…

Superconductivity · Physics 2012-06-21 A. F. Wang , X. G. Luo , Y. J. Yan , J. J. Ying , Z. J. Xiang , G. J. Ye , P. Cheng , Z. Y. Li , W. J. Hu , X. H. Chen

Superconductivity at about 15.6 K was achieved in Tb_{1-x}Ca_xFeAsO by partially substituting Tb^{3+} with Ca^{2+} in the nominal doping region x = 0.40 \sim 0.50. A detailed investigation was carried out in a typical sample with doping…

Superconductivity · Physics 2010-02-28 Gang Mu , Bin Zeng , Peng Cheng , Xiyu Zhu , Fei Han , Bing Shen , Hai-Hu Wen

By partially substituting the tri-valence element La with di-valence element Sr in $LaOFeAs$, we introduced holes into the system. For the first time, we successfully synthesized the hole doped new superconductors $(La_{1-x}Sr_x)OFeAs$. The…

Superconductivity · Physics 2008-03-28 Hai-Hu Wen , Gang Mu , Lei Fang , Huan Yang , Xiyu Zhu

In this paper we report the comparative study of superconductivity by 3d (Co), 4d (Rh), 5d (Ir) element doping in SmFeAsO. X-ray diffraction patterns indicate that the material has formed the ZrCuSiAs-type structure with a space group…

Superconductivity · Physics 2010-04-22 Yanpeng Qi , Lei Wang , Zhaoshun Gao , Dongliang Wang , Xianping Zhang , Zhiyu Zhang , Yanwei Ma

BaFe2As2 is the parent compound of the '122' iron arsenide superconductors and crystallizes with the tetragonal ThCr2Si2 type structure, space group I4/mmm. A spin density wave transition at 140 K is accompanied by a symmetry reduction to…

Superconductivity · Physics 2015-05-13 Dirk Johrendt , Rainer Poettgen

The recent discovery of superconductivity with relatively high transition temperature Tc in the layered iron-based quaternary oxypnictides La[ O1-xFx] FeAs was a real surprise. The excitement generated can be seen by the number of…