Author: Lechner, E.M.
Paper Title Page
TUPFDV002 SIMS Sample Holder and Grain Orientation Effects 401
 
  • J.W. Angle, M.J. Kelley
    Virginia Polytechnic Institute and State University, Blacksburg, USA
  • M.J. Kelley, E.M. Lechner, A.D. Palczewski, C.E. Reece
    JLab, Newport News, Virginia, USA
  • F.A. Stevie
    NCSU AIF, Raleigh, North Carolina, USA
 
  SIMS analyses for ’N-doped’ materials are becoming increasingly important. A major hurdle to acquiring quantitative SIMS results for these materials is the uncertainty of instrument calibration due to changes in sample height either from sample topography or from the sample holder itself. The CAMECA sample holder design allows for many types of samples to be analyzed. However, the cost is that the holder faceplate can bend, introducing uncertainty into the SIMS results. Here we designed and created an improved sample holder which is reinforced to prevent faceplate deflection and thereby reduce uncertainty. Simulations show that the new design significantly reduces deflection from 10 µm to 5 nm. Measurements show a reduction of calibration (RSF) uncertainty from this source from 4.1% to 0.95%. Grain orientation has long been suspected to affect RSF determination as well. A bicrystal implant standard consisting of [111] and [001] grains were repeatedly rotated 15° in between analyses. It was observed that 20% of the analyses performed on [111] grains exhibited anomalously high RSF values likely due to the changing of the grain normal with respect to the primary Cs+ beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2021-TUPFDV002  
About • Received ※ 21 June 2021 — Revised ※ 11 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 05 January 2022
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TUPFDV004 A SIMS Approach for the Analysis of Furnace Contamination 406
 
  • J.W. Angle, M.J. Kelley
    Virginia Polytechnic Institute and State University, Blacksburg, USA
  • M.J. Kelley, E.M. Lechner, A.D. Palczewski, C.E. Reece
    JLab, Newport News, Virginia, USA
  • F.A. Stevie
    NCSU AIF, Raleigh, North Carolina, USA
 
  Detection of surface contamination for SRF material is difficult due to the miniscule quantities and near atomic resolution needed. Visual inspection of samples known to have experienced surface contamination were found to have inconsistent nitride coverage after nitrogen doping. EBSD analysis suggest that nitride suppression tends to be most prevalent when deviating from the [111] and [001] zone axes. XPS suggested that tin was present as a contaminant on the surface with SIMS mass spectra also confirming its presence. SIMS depth profiles show a depletion of nitrogen content as well as an increase in car-bon content for contaminated samples.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2021-TUPFDV004  
About • Received ※ 22 June 2021 — Revised ※ 11 July 2021 — Accepted ※ 21 August 2021 — Issue date ※ 19 February 2022
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THPFDV003 SIMS Investigation of Furnace Baked Nb 761
 
  • E.M. Lechner, M.J. Kelley, A.D. Palczewski, C.E. Reece
    JLab, Newport News, Virginia, USA
  • J.W. Angle, M.J. Kelley
    Virginia Polytechnic Institute and State University, Blacksburg, USA
 
  Funding: U.S. DOE Contract No. DE-AC05-06OR23177
Results recently published by Ito et al. showed that "furnace baking" Nb SRF cavities after electropolishing yields high quality factors and anti-Q-slopes resembling that of N doped cavities. Small Nb samples were prepared following the recipe outlined by Ito. These samples were measured by SIMS to examine impurity contributions to the RF penetration layer. These diffusion profiles are modeled, and their consequences on RF properties discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2021-THPFDV003  
About • Received ※ 22 June 2021 — Accepted ※ 24 November 2021 — Issue date; ※ 15 May 2022  
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