A. Pisoni

L4Fe2As2Te1-xO4-yFy (L = Pr, Sm, Gd): A layered oxypnictide superconductor with T-c up to 45 K

The synthesis and structural and physical properties of iron lanthanide oxypnictide superconductors, L4Fe2As2Te1-xO4 (L = Pr, Sm, Gd), with transition temperature at similar to 25 K are reported. Single crystals have been grown at high pressure using the cubic anvil technique. The crystal structure consists of layers of L2O2 tetrahedra separated by alternating layers of chains of Te and of Fe2As2 tetrahedra: -L2O2-Te-L2O2-Fe2As2-L2O2-Te-L2O2-(space group: I4/mmm, a similar to 4.0, c similar to 29.6 angstrom). Substitution of oxygen by fluorine increases the critical temperature, e. g., in Gd4Fe2As2Te1-xO4-yFy up to 45 K. Magnetic torque measurements reveal an anisotropy of the penetration depths of similar to 31.

Pressure effect and superconductivity in the beta-Bi4I4 topological insulator

We report a detailed study of the transport properties of a

Crystal Structure, Transport, and Magnetic Properties of an Ir6+ Compound Ba8Al2IrO14

\ensuremath{\beta}\ensuremath{-}\mathrm{B}{\mathrm{i}}_{4}{\mathrm{I}}_{4}

Sr2Pt8-xAs: a layered incommensurately modulated metal with saturated resistivity

quasi-one-dimensional topological insulator. Electrical resistivity, thermoelectric power, thermal conductivity, and Hall coefficient measurements are consistent with the possible appearance of a charge-density-wave order at low temperatures. Both electrons and holes contribute to the conduction in

Possibility of an unconventional spin state of Ir4+ in Ba21Ir9O43 single crystal

\ensuremath{\beta}\ensuremath{-}\mathrm{B}{\mathrm{i}}_{4}{\mathrm{I}}_{4}

Magnetotransport studies of Superconducting Pr

and the dominant type of charge carrier changes with temperature as a consequence of temperature-dependent carrier densities and mobilities. Measurements of resistivity and Seebeck coefficient under hydrostatic pressure up to 2 GPa show a shift of the charge-density-wave order to higher temperatures suggesting a strongly one-dimensional character at ambient pressure. Surprisingly, superconductivity is induced in

_4

\ensuremath{\beta}\ensuremath{-}\mathrm{B}{\mathrm{i}}_{4}{\mathrm{I}}_{4}

Fe

above 10 GPa with

_2

{T}_{c}

As

of 4.0 K which is slightly decreasing upon increasing the pressure up to 20 GPa. Chemical characterization of the pressure-treated samples shows amorphization of