| Presentation | 2019-08-09 Preparation and evaluation of Nb3Ge superconducting thin films Akira Kawakami, Hirotaka Terai, Yoshinori Uzawa, |
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| PDF Download Page |  PDF download Page Link |
| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | The Nb3Ge thin film with the A15 crystal structure exhibits a superconducting transition temperature of up to 23 K, and the gap frequency is considered to reach 2 THz. In addition, it has many merits in THz band SIS mixer development, such as low resistivity over transition temperature, no crystal anisotropy, and easy reactive etching. In this study, we tried to deposit Nb3Ge thin film using co-sputtering method with high degree of freedom of film composition control. First, the molar deposition rates of Nb and Ge materials by DC sputtering were derived, and the discharge power (Nb: 300 W, Ge: 32 to 48 W) to achieve Nb: Ge = 3: 1 was calculated. The A-plane sapphire substrate was used as the substrate, and the substrate heating temperature was set to 920 ℃. The lattice constant of the obtained Nb3Ge thin film was about 0.513 nm, and the peaks of Nb5Ge3 were observed together with the peaks of Nb3Ge. The film thickness was 180 nm and the superconducting transition temperatures was about 21.0 K. The film resistivity at 25 K was 45 $mu$$Omega$cm, which is lower than that of NbTiN used in conventional SIS mixers. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | A15 / Nb3Ge / Nb5Ge3 / co-sputtering |
| Paper # | SCE2019-13 |
| Date of Issue | 2019-08-02 (SCE) |
| Conference Information | |
| Committee | SCE |
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| Conference Date | 2019/8/9(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | National Institute of Advanced Industrial Science and Technology |
| Topics (in Japanese) | (See Japanese page) |
| Topics (in English) | Device, think film, etc. |
| Chair | Satoshi Kohjiro(AIST) |
| Vice Chair | |
| Secretary | (Yokohama National Univ.) |
| Assistant | Hiroyuki Akaike(Daido Univ.) |
| Paper Information | |
| Registration To | Technical Committee on Superconductive Electronics |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Preparation and evaluation of Nb3Ge superconducting thin films |
| Sub Title (in English) | |
| Keyword(1) | A15 |
| Keyword(2) | Nb3Ge |
| Keyword(3) | Nb5Ge3 |
| Keyword(4) | co-sputtering |
| 1st Author's Name | Akira Kawakami |
| 1st Author's Affiliation | National Institute of Information and Communications Technology(NICT) |
| 2nd Author's Name | Hirotaka Terai |
| 2nd Author's Affiliation | National Institute of Information and Communications Technology(NICT) |
| 3rd Author's Name | Yoshinori Uzawa |
| 3rd Author's Affiliation | National Astronomical Observatory of Japan(NAOJ) |
| Date | 2019-08-09 |
| Paper # | SCE2019-13 |
| Volume (vol) | vol.119 |
| Number (no) | SCE-164 |
| Page | pp.pp.27-30(SCE), |
| #Pages | 4 |
| Date of Issue | 2019-08-02 (SCE) |