The semimetal antimony (Sb) element doped into hydrogen has been performed theoretically to explored high-pressure crystal structure and superconductivity of antimony hydrides. The unexpected stoichiometry $textrm{SbH}_textrm{4}$ with $P6_3/mmc$ symm
etry is found to have most negative enthalpy and embody the coexistence of covalent and ionic bonds. It is a metallic phase and stable in the pressure ranges of 127-300 GPa. Furthermore, a superconducting critical temperature ($T_c$) of 106 K is obtained at 150 GPa by employing the Allen-Dynes modified McMillan equation. In addition, an extrusive distinguishing feature is the presence of soft phonon modes, which is primary contribution to the strength of electron-phonon coupling.
An intermittent Josephson effect in the form of voltage and temperature oscillations in the voltage - current curves near 2 K is observed in pellets consisting of superconducting TaC nanocapsules coated with graphite. This phenomenon is attributed to
non-equilibrium conditions, when Cooper pairs across a junction, which stimulate the emission of photons and the feedback temperature change of the junction. It occurs in a three-dimensional granular framework composed of TaC/carbon/TaC tunneling junctions with a Mott metal-insulator transition, below the critical temperature Tc of non-ideal type-II superconductor TaC.
