Related papers: BiOCuS: A new superconducting compound with oxypni…
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…
We report appearance of superconductivity at 5K in NdO0.5F0.5BiS2 and supplement the discovery [1] of the same in layered sulfide based ZrCuSiAs type compounds. The bulk polycrystalline compound is synthesized by conventional solid state…
Very recent report [1] on observation of superconductivity in Bi4O4S3 could potentially reignite the search for superconductivity in a broad range of layered sulphides. We report here synthesis of Bi4O4S3 at 5000C by vacuum encapsulation…
Exotic superconductivity has often been discovered in materials with a layered (two-dimensional) crystal structure. The low dimensionality can affect the electronic structure and can realize high transition temperatures (Tc) and/or…
Since the discovery of superconductivity\cite{1} at 26 K in oxy-pnictide $LaFeAsO_{1-x}F_x$, enormous interests have been stimulated in the fields of condensed matter physics and material sciences. Among the five different structures in…
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…
Very recently a new family of layered materials, containing BiS2 planes was discovered to be superconducting at temperatures up to Tc=10 K, raising questions about the mechanism of superconductivity in these systems. Here, we present…
Here we report the superconductivity in the LaFeAsO1-xFx system prepared by high pressure synthesis. The highest onset superconducting transition temperature (Tc) in this La-based system is 41.0 K with the nominal composition of…
We report superconductivity in a new layered bismuth oxyselenide LaO0.5F0.5BiSe2 with the ZrCuSiAs-type structure composed of alternating superconducting BiSe2 and blocking LaO layers. The superconducting transition temperature is TC =…
The Tb-123 phase has been synthesized in single-phase form with the composition TbSr2Cu2.7Mo0.3O7 by solid-state reaction route and its phase purity is confirmed by neutron powder diffraction experiments. As-synthesized sample does not show…
Crystal structure and physical properties of the novel BiS2-based layered superconductors are briefly reviewed. Superconductivity in the BiS2-based layered compounds is induced by electron doping into the BiS2 conduction layers. The…
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$^{+4}$,…
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…
Bismuth oxysulfide Bi4O4S3, which has recently been claimed to be an exotic superconductor (Tc = 4.5 K), was investigated by magnetic susceptibility and electrical resistivity measurements as well as by electron probe microanalysis.…
The synthesis and properties of LiFeAs, a high-Tc Fe-based superconducting stoichiometric compound, are reported. Single crystal x-ray studies reveal that it crystallizes in the tetragonal PbFCl type (P4/nmm) with a=3.7914(7) A and…
Chemical doping has recently become a very important strategy to induce superconductivity especially in complex compounds. Distinguished examples include Ba-doped La$_2$CuO$_4$ (the first high temperature superconductor), K-doped BaBiO$_3$,…
we were able to develop a novel method to synthesize Fe-based oxypnictide superconductors. By using LnAs and FeO as the starting materials and a ball-milling process prior to solid-state sintering, Tc as high as 50.7 K was obtained with the…
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…
BiOCuS is a band insulator that becomes metallic upon hole doping. Superconductivity was recently reported in doped BiOCu$_{1-x}$S and attributed to spin fluctuations as a pairing mechanism. Based on first principles calculations of the…
Several decades after the discovery of superconductivity in bismuthates, the strength of their electron-phonon coupling and its evolution with doping remain puzzling. To clarify these issues, polycrystalline hole-doped…