3rd harmonic magnetometry assessment of NbTiN-based SIS structures

Conference · Sun May 01 04:00:00 EDT 2022

DOI:https://doi.org/10.18429/JACoW-SRF2021-SUPTEV016· OSTI ID:1968295

Valente, Anne-Marie ^[1]; Beverstock, David ^[2]; Antoine, Claire ^[3]; Senevirathne, Iresha ^[4]; Manos, Dennis ^[2]; Spradlin, Joshua ^[1]

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1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2. College of William and Mary, Williamsburg, VA (United States)
3. CEA Saclay
4. Old Dominion Univ., Norfolk, VA (United States)

In the quest for alternative superconducting materials to bring accelerator cavity performance beyond the bulk niobium (Nb) intrinsic limits, a promising concept proposes that superconductor-insulator-superconductor (SIS) thin film structures can delay magnetic flux penetration in accelerator cavities to higher fields [1]. NbTiN is a candidate superconductor for such structures. We have demonstrated high quality NbTiN and AlN deposited by reactive direct current magnetron sputtering (DCMS), both for individual layers and multilayers. Interface quality has been assessed for bi-layer stacks with various NbTiN and AlN thicknesses from 500 and 30 nm down to 3 and 1 nm. These SIS structures show continued sharp interfaces. The Hfp enhancement of the films was examined with 3rd harmonic magnetometry. The system was designed and built in an ongoing collaboration with CEA Saclay. It can measure 1? to 2? samples on a temperature controlled stage. This contribution presents the assessment of the first penetration field enhancement with 3rd harmonic magnetometry for standalone films and multilayer nanostructures.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1968295
• Report Number(s): JLAB-ACC-21-3605; DOE/OR/23177-5968
• Country of Publication: United States
• Language: English