Synthesis of superconducting pyrochlore RbOs2O6

Synthesis of superconducting composites

New synthesis route and magnetic structure of Tm2Mn2O7 pyrochlore.

In this work, we present a new chemical route to synthesize Tm2Mn2O7 pyrochlore, which a compound that is thermodynamically unstable at ambient pressure. Differently from the reported in the past high-pressure synthesis of the same compound applying oxides as starting materials, we have obtained a pure Tm2Mn2O7 phase by a converting TmMnO3 at 1100 °C and an oxygen pressure of 1300 bar. The stud...

Synthesis of superconducting MgÕMgB2 composites

Composites consisting of Mg and MgB2 phases were fabricated by liquid-metal infiltration following two routes. First, a preform of MgB2 powders was pressure infiltrated at 800 °C with liquid Mg, which was subsequently solidified. Second, a preform of B powders was pressure infiltrated with liquid Mg at 700 °C, resulting in partial, in situ formation of the MgB2 phase. Subsequent annealing at 95...

Scanning Tunneling Spectroscopy in the Superconducting State and Vortex Cores of the β-Pyrochlore KOs

We performed the first scanning tunneling spectroscopy measurements on the pyrochlore superconductor KOs2O6 (Tc=9.6 K) in both zero magnetic field and the vortex state at several temperatures above 1.95 K. This material presents atomically flat surfaces, yielding spatially homogeneous spectra which reveal fully gapped superconductivity with a gap anisotropy of 30%. Measurements performed at fi...

Synthesis and Characterization of Superconducting Ca1−xNaxFFeAs

A representative of the fluoride-containing iron pnictide high-temperature superconductors, namely CaFFeAs, was doped with sodium up to the composition Ca0.86Na0.14FFeAs for the first time. Single crystals with an edge length in the range of 0.1 – 2.0 mm were obtained via solid-state and flux syntheses, respectively. The composition of the crystals was verified by means of single crystal X-ray ...