Pudasaini, U. Eremeev, G.V. Kelley, M.J. Reece, C.E. Tuggle, J. JACoW Geneva, Switzerland 978-3-95450-180-9 10.18429/JACoW-NAPAC2016-WEB1CO02 English 659-662 WEB1CO02 ion niobium SRF experiment cavity Contribution to a conference proceedings 2017 2017-01 http://dx.doi.org/10.18429/JACoW-NAPAC2016-WEB1CO02 https://jacow.org/napac2016/papers/web1co02.pdf The potential for higher operating temperatures and increased accelerating gradient has attracted SRF researchers to Nb3Sn coatings on niobium for nearly 50 years. The two-step tin vapor diffusion: nucleation followed by deposition appears to be a promising technique to prepare Nb3Sn coatings on interior cavity surface. We have undertaken a fundamental materials study of the nucleation and deposition steps. Nucleation was accomplished within parameter ranges: 300 - 500 °C, 1 - 5 hrs duration, 5 mg - 1 g SnCl2 and 1 g Sn. The resulting deposit consists of (< 10%) coverage of tin particles, as determined by SEM/EDS, while XPS and SAM discovered extra tin film between these particles. Preliminary results by EBSD show no evident effect of substrate crystallography on the crystallography of the final coating. Substantial topography was found to develop during the coating growth.