Controlling $T_c$ of Iridium Films Using the Proximity Effect
Abstract
A superconducting Transition-Edge Sensor (TES) with low- is essential in a high resolution calorimetric detection. With a motivation of developing sensitive calorimeters for applications in cryogenic neutrinoless double beta decay searches, we have been investigating methods to reduce the of an Ir film down to 20 mK. Utilizing the proximity effect between a superconductor and a normal metal, we found two room temperature fabrication recipes of making Ir-based low- films. In the first approach, an Ir film sandwiched between two Au films, a Au/Ir/Au trilayer, has a tunable in the range of 20-100 mK depending on the relative thicknesses. In the second approach, a paramagnetic Pt thin film is used to create Ir/Pt bilayer with a tunable in the same range. We present detailed study of fabrication and characterization of Ir-based low- films, and compare the experimental results to theoretical models. We show that Ir-based films with predictable and reproducible critical temperature can be consistently fabricated for use in large scale detector applications.
Keywords
Cite
@article{arxiv.2010.00772,
title = {Controlling $T_c$ of Iridium Films Using the Proximity Effect},
author = {R. Hennings-Yeomans and C. L. Chang and J. Ding and A. Drobizhev and B. K. Fujikawa and S. Han and G. Karapetrov and Yu. G. Kolomensky and V. Novosad and T. O'Donnell and J. L. Ouellet and J. Pearson and T. Polakovic and D. Reggio and B. Schmidt and B. Sheff and V. Singh and R. J. Smith and G. Wang and B. Welliver and V. G. Yefremenko and J. Zhang},
journal= {arXiv preprint arXiv:2010.00772},
year = {2020}
}
Comments
5 figures, accepted in the Journal of Applied Physics