{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,30]],"date-time":"2025-10-30T16:28:27Z","timestamp":1761841707650,"version":"build-2065373602"},"reference-count":55,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2023,2,18]],"date-time":"2023-02-18T00:00:00Z","timestamp":1676678400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Rosatom","award":["No. 868-1.3-15\/15-2021"],"award-info":[{"award-number":["No. 868-1.3-15\/15-2021"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>We study operation of a superconducting quantum interference devices (SQUIDs) based on a new bilayer material. They can be used for the ultra-sensitive detection of magnetic momentum at temperatures down to milliKelvin range. Typically, thermal origin hysteresis of the symmetric SQUID current-voltage curves limits operating temperatures to T&gt;0.6Tc. We used a new bilayer material for SQUID fabrication, namely proximity-coupled superconductor\/normal-metal (S\/N) bilayers (aluminum 25 nm\/platinum 5 nm). Because of the 5 nm Pt-layer, Al\/Pt devices show nonhysteretic behavior in a broad temperature range from 20 mK to 0.8 K. Furthermore, the Al\/Pt bilayer devices demonstrate an order of magnitude lower critical current compared to the Al devices, which decreases the screening parameter (\u03b2L) and improves the modulation depth of the critical current by magnetic flux. Operation at lower temperatures reduces thermal noise and increases the SQUID magnetic field resolution. Moreover, we expect strong decrease of two-level fluctuators on the surface of aluminum due to Pt-layer oxidation protection and hence significant reduction of the 1\/f noise. Optimized geometry of Al\/Pt symmetric SQUIDs is promising for the detection of single-electron spin flip.<\/jats:p>","DOI":"10.3390\/sym15020550","type":"journal-article","created":{"date-parts":[[2023,2,20]],"date-time":"2023-02-20T04:58:23Z","timestamp":1676869103000},"page":"550","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Controlling I-V Hysteresis in Al\/Pt Bilayer Symmetric SQUIDs at Millikelvin Temperatures"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6894-2139","authenticated-orcid":false,"given":"Dmitry S.","family":"Yakovlev","sequence":"first","affiliation":[{"name":"Laboratoire de Physique et d\u2019Etude des Mat\u00e9riaux, ESPCI-Paris, PSL Research University, 75005 Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2482-7742","authenticated-orcid":false,"given":"Ivan A.","family":"Nazhestkin","sequence":"additional","affiliation":[{"name":"Russian Quantum Center, Skolkovo, 143025 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nidzhat G.","family":"Ismailov","sequence":"additional","affiliation":[{"name":"Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sergei V.","family":"Egorov","sequence":"additional","affiliation":[{"name":"Russian Quantum Center, Skolkovo, 143025 Moscow, Russia"},{"name":"Laboratory of Superconductivity, Institute of Solid State Physics, 142432 Chernogolovka, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0415-5267","authenticated-orcid":false,"given":"Vladimir N.","family":"Antonov","sequence":"additional","affiliation":[{"name":"Center for Engineering Physics, Skolkovo Institute of Science and Technology, Bolshoy Boul, 30, 121205 Moscow, Russia"},{"name":"Physics Department, Royal Holloway University of London, Egham TW20 0EX, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vladimir L.","family":"Gurtovoi","sequence":"additional","affiliation":[{"name":"Russian Quantum Center, Skolkovo, 143025 Moscow, Russia"},{"name":"Institute of Microelectronics Technology and High Purity Materials, Russian Academy of Sciences, 142432 Chernogolovka, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,2,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Clarke, J. (1996). SQUID Sensors: Fundamentals, Fabrication and Applications, Springer.","DOI":"10.1007\/978-94-011-5674-5_1"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3174","DOI":"10.1039\/C9NR08578E","article-title":"SQUID-on-tip with single-electron spin sensitivity for high-field and ultra-low temperature nanomagnetic imaging","volume":"12","author":"Anahory","year":"2020","journal-title":"Nanoscale"},{"key":"ref_3","first-page":"042010","article-title":"NANO-SQUIDs based on niobium Dayem bridges for nanoscale applications","volume":"Volume 234","author":"Granata","year":"2010","journal-title":"Journal of Physics: Conference Series"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1570","DOI":"10.1088\/0953-2048\/16\/12\/054","article-title":"Measurement of the spatial sensitivity of miniature SQUIDs using magnetic-tipped STM","volume":"16","author":"Hao","year":"2003","journal-title":"Supercond. Sci. Technol."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Huber, M.E., Koshnick, N.C., Bluhm, H., Archuleta, L.J., Azua, T., Bj\u00f6rnsson, P.G., Gardner, B.W., Halloran, S.T., Lucero, E.A., and Moler, K.A. (2008). Gradiometric micro-SQUID susceptometer for scanning measurements of mesoscopic samples. Rev. Sci. Instrum., 79.","DOI":"10.1063\/1.2932341"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Bouchiat, V. (2009). Detection of magnetic moments using a nano-SQUID: Limits of resolution and sensitivity in near-field SQUID magnetometry. Supercond. Sci. Technol., 22.","DOI":"10.1088\/0953-2048\/22\/6\/064002"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.physrep.2015.12.001","article-title":"Nano superconducting quantum interference device: A powerful tool for nanoscale investigations","volume":"614","author":"Granata","year":"2016","journal-title":"Phys. Rep."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Kudriashov, A., Babich, I., Hovhannisyan, R.A., Shishkin, A.G., Kozlov, S.N., Fedorov, A., Vyalikh, D.V., Khestanova, E., Kupriyanov, M.Y., and Stolyarov, V.S. (2022). Revealing Intrinsic Superconductivity of the Nb\/BiSbTe2Se Interface. Adv. Funct. Mater., 32.","DOI":"10.1002\/adfm.202209853"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Hazra, D., Pascal, L.M., Courtois, H., and Gupta, A.K. (2010). Hysteresis in superconducting short weak links and \u03bc-SQUIDs. Phys. Rev. B, 82.","DOI":"10.1103\/PhysRevB.82.184530"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"21475","DOI":"10.1039\/C8NR06433D","article-title":"Nano-SQUIDs with controllable weak links created via current-induced atom migration","volume":"10","author":"Keijers","year":"2018","journal-title":"Nanoscale"},{"key":"ref_11","first-page":"022019","article-title":"Development of nano and micro SQUIDs based on Al tunnel junctions","volume":"Volume 568","author":"Ishiguro","year":"2014","journal-title":"Journal of Physics: Conference Series"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1575","DOI":"10.1088\/0953-2048\/16\/12\/055","article-title":"SQUIDs: Some limits to measurement","volume":"16","author":"Gallop","year":"2003","journal-title":"Supercond. Sci. Technol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Wernsdorfer, W. (2009). From micro-to nano-SQUIDs: Applications to nanomagnetism. Supercond. Sci. Technol., 22.","DOI":"10.1088\/0953-2048\/22\/6\/064013"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Golikova, T.E., Wolf, M.J., Beckmann, D., Penzyakov, G.A., Batov, I.E., Bobkova, I., Bobkov, A.M., and Ryazanov, V.V. (2021). Controllable supercurrent in mesoscopic superconductor-normal metal-ferromagnetcrosslike Josephson structures. Supercond. Sci. Technol., 34.","DOI":"10.1088\/1361-6668\/abfd0d"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"132504","DOI":"10.1063\/1.3377897","article-title":"Josephson supercurrent in Nb\/InN-nanowire\/Nb junctions","volume":"96","author":"Frielinghaus","year":"2010","journal-title":"Appl. Phys. Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"9221","DOI":"10.1021\/acs.jpclett.2c02664","article-title":"Physical Vapor Deposition Features of Ultrathin Nanocrystals of Bi2 (Te x Se1\u2013x) 3","volume":"13","author":"Yakovlev","year":"2022","journal-title":"J. Phys. Chem. Lett."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"17059","DOI":"10.1021\/acsanm.2c03837","article-title":"Long Single Au Nanowires in Nb\/Au\/Nb Josephson Junctions: Implications for Superconducting Microelectronics","volume":"5","author":"Sotnichuk","year":"2022","journal-title":"ACS Appl. Nano Mater."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"173901","DOI":"10.1063\/5.0063274","article-title":"Scalable memory elements based on rectangular SIsFS junctions","volume":"130","author":"Karelina","year":"2021","journal-title":"J. Appl. Phys."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Angers, L., Chiodi, F., Montambaux, G., Ferrier, M., Gu\u00e9ron, S., Bouchiat, H., and Cuevas, J. (2008). Proximity dc squids in the long-junction limit. Phys. Rev. B, 77.","DOI":"10.1103\/PhysRevB.77.165408"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Courtois, H., Meschke, M., Peltonen, J., and Pekola, J.P. (2008). Origin of hysteresis in a proximity Josephson junction. Phys. Rev. Lett., 101.","DOI":"10.1103\/PhysRevLett.101.067002"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Kumar, N., Winkelmann, C., Biswas, S., Courtois, H., and Gupta, A.K. (2015). Controlling hysteresis in superconducting constrictions with a resistive shunt. Supercond. Sci. Technol., 28.","DOI":"10.1088\/0953-2048\/28\/7\/072003"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1451","DOI":"10.1063\/1.101583","article-title":"Performance of dc SQUIDs with resistively shunted inductance","volume":"55","author":"Foglietti","year":"1989","journal-title":"Appl. Phys. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Nagel, J., Konovalenko, K., Kemmler, M., Turad, M., Werner, R., Kleisz, E., Menzel, S., Klingeler, R., B\u00fcchner, B., and Kleiner, R. (2010). Resistively shunted YBa2Cu3O7 grain boundary junctions and low-noise SQUIDs patterned by a focused ion beam down to 80 nm linewidth. Supercond. Sci. Technol., 24.","DOI":"10.1088\/0953-2048\/24\/1\/015015"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1151","DOI":"10.1109\/20.92493","article-title":"Simple DC-SQUID system based on a frequency modulated relaxation oscillator","volume":"25","author":"Muck","year":"1989","journal-title":"IEEE Trans. Magn."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Hovhannisyan, R.A., Kapran, O.M., Golod, T., and Krasnov, V.M. (2021). Accurate Determination of the Josephson Critical Current by Lock-In Measurements. Nanomaterials, 11.","DOI":"10.3390\/nano11082058"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"233907","DOI":"10.1063\/1.4843856","article-title":"Proximity effect bilayer nano superconducting quantum interference devices for millikelvin magnetometry","volume":"114","author":"Blois","year":"2013","journal-title":"J. Appl. Phys."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"115004","DOI":"10.1088\/1361-6668\/aada2e","article-title":"Peculiar superconducting properties of a thin film superconductor\u2013normal metal bilayer with large ratio of resistivities","volume":"31","author":"Vodolazov","year":"2018","journal-title":"Supercond. Sci. Technol."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Blois, A., Rozhko, S., Hao, L., Gallop, J., and Romans, E. (2016). Heat propagation models for superconducting nanobridges at millikelvin temperatures. Supercond. Sci. Technol., 30.","DOI":"10.1088\/0953-2048\/30\/1\/014003"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/ncomms5119","article-title":"Evidence for interacting two-level systems from the 1\/f noise of a superconducting resonator","volume":"5","author":"Burnett","year":"2014","journal-title":"Nat. Commun."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Barone, C., Rotzinger, H., Voss, J.N., Mauro, C., Sch\u00f6n, Y., Ustinov, A.V., and Pagano, S. (2020). Current-resistance effects inducing nonlinear fluctuation mechanisms in granular aluminum oxide nanowires. Nanomaterials, 10.","DOI":"10.3390\/nano10030524"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Burin, A.L., Matityahu, S., and Schechter, M. (2015). Low-temperature 1\/f noise in microwave dielectric constant of amorphous dielectrics in Josephson qubits. Phys. Rev. B, 92.","DOI":"10.1103\/PhysRevB.92.174201"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"22027","DOI":"10.1038\/s41598-022-26475-6","article-title":"Current dependence of the negative magnetoresistance in superconducting NbN nanowires","volume":"12","author":"Sofer","year":"2022","journal-title":"Sci. Rep."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Jouan, A., Hurand, S., Singh, G., Lesne, E., Barth\u00e9l\u00e9my, A., Bibes, M., Ulysse, C., Saiz, G., Feuillet-Palma, C., and Lesueur, J. (2022). Multiband Effects in the Superconducting Phase Diagram of Oxide Interfaces. Adv. Mater. Interfaces, 9.","DOI":"10.1002\/admi.202201392"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"M\u00fcller, C., Lisenfeld, J., Shnirman, A., and Poletto, S. (2015). Interacting two-level defects as sources of fluctuating high-frequency noise in superconducting circuits. Phys. Rev. B, 92.","DOI":"10.1103\/PhysRevB.92.035442"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Bilmes, A., Zanker, S., Heimes, A., Marthaler, M., Sch\u00f6n, G., Weiss, G., Ustinov, A.V., and Lisenfeld, J. (2017). Electronic decoherence of two-level systems in a Josephson junction. Phys. Rev. B, 96.","DOI":"10.1103\/PhysRevB.96.064504"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/S0168-9002(99)01320-0","article-title":"Calculation of TC in a normal-superconductor bilayer using the microscopic-based Usadel theory","volume":"444","author":"Martinis","year":"2000","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"105028","DOI":"10.1063\/1.5100259","article-title":"On-chip integrable planar NbN nanoSQUID with broad temperature and magnetic-field operation range","volume":"9","author":"Holzman","year":"2019","journal-title":"AIP Adv."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Russo, R., Esposito, E., Crescitelli, A., Di Gennaro, E., Granata, C., Vettoliere, A., Cristiano, R., and Lisitskiy, M. (2016). NanoSQUIDs based on niobium nitride films. Supercond. Sci. Technol., 30.","DOI":"10.1088\/1361-6668\/30\/2\/024009"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Faley, M., Fiadziushkin, H., Frohn, B., Sch\u00fcffelgen, P., and Dunin-Borkowski, R. (2022). TiN nanobridge Josephson junctions and nanoSQUIDs on SiN-buffered Si. Supercond. Sci. Technol., 35.","DOI":"10.1088\/1361-6668\/ac64cd"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Faley, M.I., Liu, Y., and Dunin-Borkowski, R.E. (2021). Titanium nitride as a new prospective material for nanoSQUIDS and superconducting nanobridge electronics. Nanomaterials, 11.","DOI":"10.3390\/nano11020466"},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Shishkin, A., Skryabina, O., Gurtovoi, V., Dizhur, S., Faley, M., Golubov, A., and Stolyarov, V. (2020). Planar MoRe-based direct current nanoSQUID. Supercond. Sci. Technol., 33.","DOI":"10.1088\/1361-6668\/ab877c"},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Rigetti, C., Gambetta, J.M., Poletto, S., Plourde, B., Chow, J.M., C\u00f3rcoles, A., Smolin, J.A., Merkel, S.T., Rozen, J., and Keefe, G.A. (2012). Superconducting qubit in a waveguide cavity with a coherence time approaching 0.1 ms. Phys. Rev. B, 86.","DOI":"10.1103\/PhysRevB.86.100506"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Kennedy, O., Burnett, J., Fenton, J., Constantino, N., Warburton, P., Morton, J., and Dupont-Ferrier, E. (2019). Tunable Nb superconducting resonator based on a constriction nano-SQUID fabricated with a Ne focused ion beam. Phys. Rev. Appl., 11.","DOI":"10.1103\/PhysRevApplied.11.014006"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Levenson-Falk, E., Vijay, R., Antler, N., and Siddiqi, I. (2013). A dispersive nanoSQUID magnetometer for ultra-low noise, high bandwidth flux detection. Supercond. Sci. Technol., 26.","DOI":"10.1088\/0953-2048\/26\/5\/055015"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1007\/BF00655097","article-title":"DC SQUID: Noise and optimization","volume":"29","author":"Tesche","year":"1977","journal-title":"J. Low Temp. Phys."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Soloviev, I., Klenov, N., Schegolev, A., Bakurskiy, S., and Kupriyanov, M.Y. (2016). Analytical derivation of DC SQUID response. Supercond. Sci. Technol., 29.","DOI":"10.1088\/0953-2048\/29\/9\/094005"},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Lam, S.K., Clem, J.R., and Yang, W. (2011). A nanoscale SQUID operating at high magnetic fields. Nanotechnology, 22.","DOI":"10.1088\/0957-4484\/22\/45\/455501"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"192507","DOI":"10.1063\/1.2917580","article-title":"Measurement and noise performance of nano-superconducting-quantum-interference devices fabricated by focused ion beam","volume":"92","author":"Hao","year":"2008","journal-title":"Appl. Phys. Lett."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Dausy, H., Nulens, L., Raes, B., Van Bael, M.J., and Van de Vondel, J. (2021). Impact of Kinetic Inductance on the Critical-Current Oscillations of Nanobridge SQUIDs. Phys. Rev. Appl., 16.","DOI":"10.1103\/PhysRevApplied.16.024013"},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Aref, T., Levchenko, A., Vakaryuk, V., and Bezryadin, A. (2012). Quantitative analysis of quantum phase slips in superconducting Mo76Ge24 nanowires revealed by switching-current statistics. Phys. Rev. B, 86.","DOI":"10.1103\/PhysRevB.86.024507"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"223112","DOI":"10.1063\/1.3443716","article-title":"Approaching ideal weak link behavior with three dimensional aluminum nanobridges","volume":"96","author":"Vijay","year":"2010","journal-title":"Appl. Phys. Lett."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Poli, N., Morten, J.P., Urech, M., Brataas, A., Haviland, D.B., and Korenivski, V. (2008). Spin injection and relaxation in a mesoscopic superconductor. Phys. Rev. Lett., 100.","DOI":"10.1103\/PhysRevLett.100.136601"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"713","DOI":"10.1038\/416713a","article-title":"Electrical detection of spin precession in a metallic mesoscopic spin valve","volume":"416","author":"Jedema","year":"2002","journal-title":"Nature"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"211106","DOI":"10.1063\/1.4880099","article-title":"Silver-epoxy microwave filters and thermalizers for millikelvin experiments","volume":"104","author":"Scheller","year":"2014","journal-title":"Appl. Phys. Lett."},{"key":"ref_55","doi-asserted-by":"crossref","unstructured":"Stolyarov, V.S., Roditchev, D., Gurtovoi, V.L., Kozlov, S.N., Yakovlev, D.S., Skryabina, O.V., Vinokur, V.M., and Golubov, A.A. (2022). Resonant Oscillations of Josephson Current in Nb-Bi2Te2. 3Se0. 7-Nb Junctions. Adv. Quantum Technol., 5.","DOI":"10.1002\/qute.202100124"}],"container-title":["Symmetry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-8994\/15\/2\/550\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:36:08Z","timestamp":1760121368000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-8994\/15\/2\/550"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,2,18]]},"references-count":55,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2023,2]]}},"alternative-id":["sym15020550"],"URL":"https:\/\/doi.org\/10.3390\/sym15020550","relation":{},"ISSN":["2073-8994"],"issn-type":[{"type":"electronic","value":"2073-8994"}],"subject":[],"published":{"date-parts":[[2023,2,18]]}}}