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Related papers: Fluorine effect in layered oxypnictide LaOFeAs

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We report on doping dependencies of structural parameters and superconducting transition temperatures in the solid solution (Ba1-xKx)Fe2As2. As the main effect of doping on the crystal structure, we find linear decreasing As-Fe-As bond…

Superconductivity · Physics 2008-09-26 Marianne Rotter , Michael Pangerl , Marcus Tegel , Dirk Johrendt

We report superconductivity induced in films of the non-superconducting, antiferromagnetic parent material FeTe by low temperature oxygen incorporation in a reversible manner. X-ray absorption shows that oxygen doping changes the nominal Fe…

Superconductivity · Physics 2010-07-26 Yuefeng Nie , Donald Telesca , Joseph I. Budnick , Boris Sinkovic , Barrett O. Wells

The competition of magnetic order and superconductivity is a key element in the physics of all unconventional superconductors, e.g. in high-transition-temperature cuprates 1, heavy fermions 2 and organic superconductors3. Here…

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 Fe-based Oxypnicide superconductors have generated a huge amount of interest; they are a high temperature superconductor, with a Tc of 55K, but do not have the two dimensional copper oxygen layer that was thought essential for…

We report the antimony (Sb) doping effect in a prototype system of iron-based supercon-ductors LaFeAsO1-yFy (y=0, 0.1, 0.15). X-ray powder diffraction indicates that the lattice pa-rameters increase with Sb content within the doping limit.…

Superconductivity · Physics 2010-08-17 Cao Wang , Zhifeng Ma , Shuai Jiang , Yuke Li , Zhu'an Xu , Guanghan Cao

We report the realization of superconductivity by an isovalent doping with phosphorus in LaFeAsO. X-ray diffraction shows that, with the partial substitution of P for As, the Fe$_2$As$_2$ layers are squeezed while the La$_2$O$_2$ layers are…

Superconductivity · Physics 2009-08-12 Cao Wang , Shuai Jiang , Qian Tao , Zhi Ren , Yuke Li , Linjun Li , Chunmu Feng , Jianhui Dai , Guanghan Cao , Zhu'an Xu

We have employed a new route to synthesize single phase F-doped LaOFeAs compound and confirmed the superconductivity above 20 K in this Fe-based system. We show that the new superconductor has a rather high upper critical field of about 54…

Superconductivity · Physics 2009-11-13 G. F. Chen , Z. Li , G. Li , J. Zhou , D. Wu , J. Dong , W. Z. Hu , P. Zheng , Z. J. Chen , H. Q. Yuan , J. Singleton , J. L. Luo , N. L. Wang

Doping of strongly layered ionic oxides is an established paradigm for creating novel electronic behavior. This is nowhere more apparent than in superconductivity, where doping gives rise to high temperature superconductivity in cuprates…

Superconductivity · Physics 2013-07-17 E. R. Ylvisaker , W. E. Pickett

The layered compound LaOBiSSe was successfully synthesized by a two-step solid-state reaction method, which is isostructural with the quaternary compound LaOBiS2 indicated by the powder X-ray diffraction characterization, and the crystal…

Superconductivity · Physics 2014-05-01 Xiao-Chuan Wang , Dong-Yun Chen , Qi Guo , Jia Yu , Bin-Bin Ruan , Qing-Ge Mu , Gen-Fu Chen , Zhi-An Ren

N-type doping of high-resistance wide bandgap semiconductors, wurtzite high-Mg-content MgxZn1-xO for instance, has always been a fundamental application-motivated research issue. Herein, we report a solution to enhancing the conductivity of…

Using as a model the Hubbard Hamiltonian we determine various basic properties of electron-doped cuprate superconductors like ${Nd}_{2-x}{Ce}_{x}{CuO}_{4}$ and ${Pr}_{2-x}{Ce}_{x}{CuO}_{4}$ for a spin-fluctuation-induced pairing mechanism.…

Superconductivity · Physics 2009-10-31 D. Manske , I. Eremin , K. H. Bennemann

We consider 2D surface superconductivity in high magnetic fields parallel to the surface. We demonstrate that the spin-orbit interaction at the surface changes the properties of the inhomogeneous superconducting…

Superconductivity · Physics 2009-11-07 Victor Barzykin , Lev P. Gor'kov

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…

A systematic investigation has been performed by synthesis and comprehensive characterization of a series of SmFe1-xCuxAsO0.8F0.2 bulks (x = 0 to 0.2). These samples are well characterized by structural, Raman spectroscopy, microstructural,…

Using the numerical unrestricted Hartree-Fock approach, we study the ground state of a two-orbital model describing newly discovered FeAs-based superconductors. We observe the competition of a $(0, \pi)$ mode spin-density wave and the…

Superconductivity · Physics 2015-05-13 Shuo Yang , Wen-Long You , Shi-Jian Gu , Hai-Qing Lin

We describe a new methodology of synthesizing the oxypnictide superconductors with potassium fluoride as a source as a source of fluorine instead of LaF3. This route also allows the substitution of potassium at lanthanum sites which leads…

Superconductivity · Physics 2008-06-24 S. Singh , J. Prakash , D. Srikala , A. K. Singh , S. Patnaik , A. K. Ganguli

We have successfully synthesized Ce based oxypnictide with fluorine doping (CeO_{1-x}F_xFeAs) by a two step solid state reaction method. Detailed XRD and EDX confirm the crystal structure and chemical compositions. We observe that an…

Superconductivity · Physics 2009-03-24 J. Prakash , S. J. Singh , S. Patnaik , A. K. Ganguli

We use neutron scattering to study the structural and magnetic phase transitions in the iron pnictides CeFeAsO1-xFx as the system is tuned from a semimetal to a high-transition-temperature (high-Tc) superconductor through Fluorine (F)…

Here we report the superconductivity in the iron-based oxyarsenide Sm[O1-xFx]FeAs, with the onset resistivity transition temperature at 55.0 K and Meissner transition at 54.6 K. This compound has the same crystal structure as LaOFeAs with…