Pressure dependence of the transport critical current density in optimally doped Hg0.82Re0.18Ba2Ca2Cu3O8+δ polycrystalline compound

We report a study on the pressure dependence of the transport critical current density (Jct) in a polycrystalline sample of Hg0.82Re0.18Ba2Ca2Cu3O8+δ with the optimum oxygen content. The rate of increase for Jct with pressure is ∂PJct/Jct=7.1×10−2 kbar−1 while ∂PTc/Tc=1.67×10−3 kbar−1. The data were analyzed within the framework of a phenomenological model, which takes into account the granular structure of the ceramic sample. An analytical expression is found which relates the ∂PJct/Jct and ∂PTc/Tc rates. In our experimental conditions, the increase of the superconductor gap at zero temperature was considered to be the main factor responsible for the increase of Jct with pressure.