Related papers: Non-cubic layered structure of Ba(1-x)K(x)BiO3 sup…
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…
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…
Structural and optoelectronic properties of BaThO3 cubic perovskite are calculated using all electrons full potential linearized augmented plane wave (FP-LAPW) method. Wide and direct band gap, 5.7 eV, of the compound predicts that it can…
Motivated by the recent synthesis of Ba$_2$CuO$_{3+\delta}$ (BCO), a high temperature superconducting cuprate with putative $d_{3z^2-r^2}$ ground state symmetry, we investigated its electronic structure by means of Cu $L_3$ x-ray absorption…
Layered superconductors have provided some interesting fields in condensed matter physics owing to the low dimensionality of their electronic states. For example, the high-Tc (high transition temperature) cuprates and the Fe-based…
An intact CuO$_2$ plane is widely believed to be a prerequisite for the high-$T_c$ superconductivity in cuprate superconductors. However, an exception may exist in the superconducting Ba$_2$CuO$_{3+\delta}$ materials where CuO chains play a…
The crystal structure of the candidate topological superconductor Cu$_x$Bi$_2$Se$_3$ was studied by single-crystal neutron diffraction using samples obtained by inserting the Cu dopant electrochemically. Neither structural refinements nor…
A new layered Ti-based pnictide oxide superconductor, Ba1-xNaxTi2Sb2O (0.0 <= x <= 0.33), is reported. X-ray studies reveal it crystallizes in the tetragonal CeCr2Si2C structure. The undoped parent compound, BaTi2Sb2O (P4/mmm;…
This paper discusses the synthesis, characterization, and comprehensive study of Ba-122 single crystals with various substitutions and various $T_c$. The paper uses five complementary techniques to obtain a self-consistent set of data on…
The observation of superconductivity at 4.3 K in a new crystalline form of Na0.3CoO2*1.3H2O is reported. The new superconductor has three layers of CoO6 octahedra per crystallographic unit cell, in contrast to the previously reported…
A quaternary compound Bi3O2S2Cl, which consists of novel [BiS2Cl]2-layers, is reported. It adopts a layered structure of the space group I4/mmm (No. 139) with lattice parameters: a = 3.927(1) {\AA}, c = 21.720(5) {\AA}. In this compound,…
The doped perovskite BaBiO$_3$ exhibits a maximum superconducting transition temperature ($T_c$) of 34 K and was the first high-$T_c$ oxide to be discovered, yet pivotal questions regarding the nature of both the metallic and…
We report on the crystal growth and characterization of ABi3 (A=Ba,Sr) superconductors. Single crystals of both compounds were grown by the self-flux technique. BaBi3 crystallized in a tetragonal structure with space group P4/mmm and SrBi3…
Although copper and bismuth do not form any compounds at ambient conditions, two intermetallics, CuBi and Cu$_{11}$Bi$_7$, were recently synthesized at high pressures. Here we report on the discovery of additional copper-bismuth phases at…
Oxygen-scavenging at oxide heterointerfaces has emerged as a powerful route for stabilizing metastable phases that exhibit interesting phenomena, including high-mobility two-dimensional electron gases and high T$_{c}$ superconductivity. We…
We have studied the electronic structure of unoccupied states measured by O K-edge and Cu L-edge x-ray absorption spectroscopy (XAS), combined with crystal structure studied by high resolution powder x-ray diffraction (HRPXRD), of…
Superconductivity, at 2-3 K, was observed in a novel phase of the ternary Li-Rh-B system. The structural phase exhibits a large noncentrosymmetric cubic unit cell with the a-parameter being within 1.208 \leq a \leq 1.215 nm. This phase is…
In 2012, we discovered superconductivity in Bi4O4S3 and LaO1-xFxBiS2, whose crystal structures are composed of alternate stacks of a BiS2-type conduction layer and a blocking layer. Since the discovery, many related superconductors and…
The crystal structure of Pb$_{10}$(PO$_4$)$_6$O, the proposed matrix for the potential room-temperature superconductor LK-99, Pb$_{10-x}$Cu$_x$(PO$_4$)$_6$O ($x = 0.9-1.0$), has been reinvestigated by single-crystal X-ray diffraction using…
We report synthesis, characterization, and physical properties of layered bismuth-sulfide compounds La2O2Bi3-xPb1+xS6. We synthesized a new La2O2Bi3PbS6 compound, whose crystal structure is similar to those of the La2O2Bi3AgS6…