JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - CONF AU - Kelley, M.M. AU - Arias, T. AU - Sitaraman, N. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Lesage, Ana ED - Schaa, Volker R.W. TI - Ab Initio Theory of the Impact of Grain Boundaries on the Superconducting Properties of Nb₃Sn J2 - Proc. of SRF2021, East Lansing, MI, USA, 28 June-02 July 2021 CY - East Lansing, MI, USA T2 - International Conference on RF Superconductivity T3 - 20 LA - english AB - For over 50 years experiments have repeatedly demonstrated that the superconducting performance of Nb₃Sn is profoundly sensitive to grain boundaries (GBs), but only recently has a microscopic theory emerged. Here we present the first comprehensive, ab initio study of GBs in Nb₃Sn*. While most conventional superconductors, such as Nb, are not significantly impacted by GBs, Nb₃Sn is much more sensitive to defects and disorder owing to its short coherence length of ~3 nm. Indeed, experiments suggest a link between GB stoichiometry and the performance of Nb₃Sn superconducting radio frequency (SRF) cavities, and mesoscopic simulations point to GBs as a candidate mechanism that lowers the vortex-entry field in Nb₃Sn SRF cavities. Our density-functional theory (DFT) calculations on tilt and twist GBs provide direct insight into antisite defect formation near GBs and how local electronic properties are impacted by clean GBs and by GBs with added point defects. Ultimately, we will show how GB composition affects the local Tc around GBs in Nb₃Sn to elucidate recent SRF experiments and provide insight on promising modifications to the growth procedure of Nb₃Sn to optimize its SRF performance. PB - JACoW Publishing CP - Geneva, Switzerland SP - 62 EP - 66 KW - cavity KW - SRF KW - electron KW - niobium KW - site DA - 2022/10 PY - 2022 SN - 2673-5504 SN - 978-3-95450-233-2 DO - doi:10.18429/JACoW-SRF2021-SUPFDV002 UR - https://jacow.org/srf2021/papers/supfdv002.pdf ER -