Energetic Condensation Growth of MgB2 Thin-Films for SRF Applications
We report single-step vacuum growth of a stoichiometric superconducting thin film of MgB2, using AASC?s cathodic arc deposition process. Energetic condensation using cathodic arcs produces non-equilibrium fast ions (~50-100eV) that allow growth modes on relatively low temperature substrates. We have demonstrated a film Tc of 34K with MgB2 by depositing at 275 °C in a single step, from a stoichiometric, solid MgB2 source. In a subsequent experiment, the single-step coated samples (on c-plane sapphire) were ex-situ annealed. Post-deposition anneal temperature ranged from 825?900K, for 15 minutes. The annealed film also showed a transition at 30K. An MgB2 film was also deposited over a 50mm diameter circle on a Buffered Chemically Polished Niobium substrate for future RF evaluation in a cavity. The depositions spanned a range of substrate temperatures from 550-675 K. The films began to change in appearance form silver to black as substrate temperature was increased, indicating a decreasing magnesium content in the films. Future plans are to reduce oxygen contamination and to use our filtered cathodic arc to deposit smoother films.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Nuclear Physics (NP)
- DOE Contract Number:
- AC05-06OR23177
- OSTI ID:
- 1999193
- Report Number(s):
- JLAB-ACC-09-1072; DOE/OR/23177-1107
- Resource Relation:
- Conference: SRF2009, Berlin, Germany, September 20, 2009
- Country of Publication:
- United States
- Language:
- English
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