Non-Fermi-Liquid Behavior of Superconducting SnH.

The chemical interaction of Sn with H by X-ray diffraction methods at pressures of 180-210 GPa is studied. A previously unknown tetrahydride SnH with a cubic structure (fcc) exhibiting superconducting properties below T  = 72 K is obtained; the formation of a high molecular C2/m-SnH superhydride and several lower hydrides, fcc SnH , and C2-Sn H , is also detected. The temperature dependence of critical current density J (T) in SnH yields the superconducting gap 2Δ(0) = 21.

Vortex Phase Dynamics in Yttrium Superhydride YH at Megabar Pressures.

A comprehensive study of vortex phases and vortex dynamics is presented for a recently discovered high-temperature superconductor YH with (onset) of 215 K under a pressure of 200 GPa. The thermal activation energy () is derived within the framework of the thermally activated flux flow (TAFF) theory. The activation energy yields a power law dependence ∝ on magnetic field with a possible crossover at a field around 8-10 T.

Effect of Magnetic Impurities on Superconductivity in LaH.

Polyhydrides are a novel class of superconducting materials with extremely high critical parameters, which is very promising for sensor applications. On the other hand, a complete experimental study of the best so far known superconductor, lanthanum superhydride LaH , encounters a serious complication because of the large upper critical magnetic field H (0), exceeding 120-160 T. It is found that partial replacement of La atoms by magnetic Nd atoms results in significant suppression of superconductivity in LaH : each at% of Nd causes a decrease in T by 10-11 K, helping to control the critical parameters of this compound.

Anomalous High-Temperature Superconductivity in YH.

Pressure-stabilized hydrides are a new rapidly growing class of high-temperature superconductors, which is believed to be described within the conventional phonon-mediated mechanism of coupling. Here, the synthesis of one of the best-known high-T superconductors-yttrium hexahydride -YH is reported, which displays a superconducting transition at ≈224 K at 166 GPa. The extrapolated upper critical magnetic field B (0) of YH is surprisingly high: 116-158 T, which is 2-2.

Superconductivity in Cu Co-Doped SrBiSe Single Crystals.

In this study, we grew Cu co-doped single crystals of a topological superconductor candidate Sr x Bi 2 Se 3 , and studied their structural and transport properties. We reveal that the addition of even as small an amount of Cu co-dopant as 0.6 atomic %, completely suppresses superconductivity in Sr x Bi 2 Se 3 .