X-ray Pole Figure Analysis on Fiber Textured Epitaxial Niobium Films for SRF Cavities

Conference · Sun Nov 01 04:00:00 EST 2009

OSTI ID:1999202

Seo, Kang; Zhao, Xin; Valente, Anne-Marie; Phillips, Harry; Reece, Charles; Krishnan, Mahadevan; Bures, B.; Wilson-Elliott, K.

Single and large grain Nb films are of interest to reduce the cost of SRF cavities. The structural properties and SRF potential of Nb films obtained by coaxial energetic deposition (CEDTM) in an ultra-high vacuum process are compared and discussed. The CEDTM is a hybrid technique with both energetic ion deposition and implantation phases based on cathodic arc plasma sources, which are copious generators of condensable energetic (20-200 eV), multiply charged ions from metal or alloy cathodes. The X-ray pole figure of the thin films revealed grain orientations on Nb films grown at different substrate temperatures that indicate good structural and electrical properties. Single crystalline 110 epilayers of Nb films are grown on a-plane sapphire substrates at 400 degreeC, but at lower temperature, there are two kinds of twins in which the grains are rotated by ~45 degree about the film normal. RRR of ~129 and Tc=9.2K were measured on a Nb film on a-plane sapphire substrate at 400 degreeC, dropping to ~4 on a room temperature substrate.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1999202
• Report Number(s): JLAB-ACC-09-1075; DOE/OR/23177-1109
• Country of Publication: United States
• Language: English