Supercondctivity in PbBe Multilayer Thin Film

It was recently proposed by X. H. Zheng et al [1], that hetero-structures of Pb and Be would exhibit high-temperature superconductivity at 36K due to Beryllium's high Debye temperature and low mass. To investigate this we have alternately grown thin films of Pb and Be in a layered structure by the use of a vacuum evaporator. Layers were approximately 10nm each for a total film thickness of <100nm. Magnetisation measurements show a transition at ~10K, slightly above the bulk Tc of Pb, which persists to fields significantly higher than the critical field of Pb. This shows promise for Pb-Be layered systems and may be further improved with thinner, higher quality layers.

[1] McMillan Formula: long-standing myth and a novel implementation to reveal high Tc in beryllium-based alloys. X. H. Zheng, J. X. Zheng. arXiv:1907.07597