SRF2019 - List of Authors (Pack, A.R.)

Paper	Title	Page
MOP010	Ab Initio Calculations on the Growth and Superconducting Properties of Nb₃Sn	39
SUSP023	use link to see paper's listing under its alternate paper code
	N. Sitaraman, T. Arias, P. Cueva, M.M. Kelley, D.A. Muller Cornell University, Ithaca, New York, USA J.M. Carlson, A.R. Pack, M.K. Transtrum Brigham Young University, Provo, USA M. Liepe, R.D. Porter, Z. Sun Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: This research was funded by the Center for Bright Beams. In this work, we employ theoretical ab initio techniques to solve mysteries and gain new insights in Nb₃Sn SRF physics. We determine the temperature dependence of Nb₃Sn antisite defect formation energies, and discuss the implications of these results for defect segregation. We calculate the phonon spectral function for Nb₃Sn cells with different combinations of antisite defects and use these results to determine Tc as a function of stoichiometry. These results allow for the first-ever determination of Tc in the tin-rich regime, where experimental measurements are unavailable and which is critical to understanding the impact of tin-rich grain boundaries on superconducting cavity performance. Finally, we propose a theory for the growth mechanism of Nb₃Sn growth on a thick oxide, explaining the puzzling disappearing droplet behavior of Sn on Nb oxide and suggesting how in general an oxide layer reacts with Sn to produce a uniform Nb₃Sn layer.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP010
About •	paper received ※ 02 July 2019 paper accepted ※ 03 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOP010

Ab Initio Calculations on the Growth and Superconducting Properties of Nb₃Sn

39

SUSP023

use link to see paper's listing under its alternate paper code

N. Sitaraman, T. Arias, P. Cueva, M.M. Kelley, D.A. Muller
Cornell University, Ithaca, New York, USA
J.M. Carlson, A.R. Pack, M.K. Transtrum
Brigham Young University, Provo, USA
M. Liepe, R.D. Porter, Z. Sun
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: This research was funded by the Center for Bright Beams.
In this work, we employ theoretical ab initio techniques to solve mysteries and gain new insights in Nb₃Sn SRF physics. We determine the temperature dependence of Nb₃Sn antisite defect formation energies, and discuss the implications of these results for defect segregation. We calculate the phonon spectral function for Nb₃Sn cells with different combinations of antisite defects and use these results to determine Tc as a function of stoichiometry. These results allow for the first-ever determination of Tc in the tin-rich regime, where experimental measurements are unavailable and which is critical to understanding the impact of tin-rich grain boundaries on superconducting cavity performance. Finally, we propose a theory for the growth mechanism of Nb₃Sn growth on a thick oxide, explaining the puzzling disappearing droplet behavior of Sn on Nb oxide and suggesting how in general an oxide layer reacts with Sn to produce a uniform Nb₃Sn layer.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP010

About •

paper received ※ 02 July 2019 paper accepted ※ 03 July 2019 issue date ※ 14 August 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)