Influence of the buffer layer on the growth of superconducting films based on mercury

Abstract

Thin films of mercury based superconductors were prepared on R-plane sapphire with a CeO2 buffer layer by a two-step process involving the deposition of the Hg-free precursor and ex situ mercuration in a sealed quartz tube. We used CeO2 buffer layers of different thicknesses to study their influence on the phase composition and properties of the final films. We succeeded in preparing a Hg-1223 superconducting phase on thin CeO2 buffered (10 nm) R-plane sapphire with a critical temperature TC0 up to 122.5 K and critical current density JC up to 4 × 105 A cm−2.