Physica C-superconductivity and Its Applications最新文献

{"title":"Evaluation of the structural, morphological, and magnetic properties of the RE-358, RE-123, RE-Ca0.1 with RE = Gd and Sm superconductors","authors":"C.C. Canaria Camargo ,&nbsp;I.M. Saavedra Gaona ,&nbsp;D.A. Landinez Tellez ,&nbsp;C.A. Parra Vargas","doi":"10.1016/j.physc.2025.1354647","DOIUrl":"10.1016/j.physc.2025.1354647","url":null,"abstract":"<div><div>In this work, we report the production of the cuprate-type <em>RE</em>₃Ba₅Cu₈O_18-δ (<em>RE-</em>358), REBa₂Cu₃O_7-δ (<em>RE-</em>123), and <em>RE</em>Ba_1.9Ca_0.1Cu₃O_7-δ (<em>RE</em>-Ca0.1), with (<em>RE</em> = Sm and Gd) superconductors. The materials were synthesized using the solid-state reaction method, with sintering temperatures ranging from 850 to 890°C. A comparative analysis of the three systems and the influence of the substituent cation on their structural, morphological, and magnetic properties was carried out through characterization techniques such as XRD, SEM, and VSM. For the <em>RE</em>-358 system, a predominant orthorhombic phase (space group <em>Pmm2</em> (25)) was identified, whereas the <em>RE</em>-123 and <em>RE</em>-Ca0.1 systems exhibited an orthorhombic structure (space group <em>Pmmm</em> (47)). SEM results revealed homogeneous and relatively smooth surfaces, attributed to the solid-state sintering reactions at high temperatures. Using vibrating sample magnetometry, magnetization curves were obtained as a function of temperature in Zero Field Cooled/Field Cooled (ZFC/FC) mode. From these measurements, the critical temperature (<span><math><msub><mi>T</mi><mi>c</mi></msub></math></span>) and irreversibility temperature (<span><math><msub><mi>T</mi><mrow><mi>i</mi><mi>r</mi><mi>r</mi></mrow></msub></math></span>) values were determined. Magnetic studies reveal that the samples exhibit a superconducting transition within the temperature range of 65 - 86 K, depending on the rare earth (<em>RE</em>) element and the system. Thermodynamic fluctuations in magnetic measurements were analyzed using the Bulavskii, Ledvij and Kogan (BKL) model that analyzes fluctuations from the Lawrence-Doniach (LD) model, with this model the parameters of penetration depth <span><math><msub><mi>λ</mi><mrow><mi>a</mi><mi>b</mi></mrow></msub></math></span>, coherence lengths <span><math><msub><mi>ξ</mi><mrow><mi>a</mi><mi>b</mi></mrow></msub></math></span>, and <span><math><msub><mi>ξ</mi><mi>c</mi></msub></math></span>, corresponding to the <em>ab</em> planes and the <em>c</em> direction, respectively, were obtained.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"630 ","pages":"Article 1354647"},"PeriodicalIF":1.3,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143225997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The determination of the superconductivity mechanism of the ternary metal phosphide WRuP","authors":"I. Al-Chalabi,&nbsp;S. Bağcı,&nbsp;H.Y. Uzunok,&nbsp;E. Karaca,&nbsp;H.M. Tütüncü","doi":"10.1016/j.physc.2024.1354645","DOIUrl":"10.1016/j.physc.2024.1354645","url":null,"abstract":"<div><div>The properties of orthorhombic WRuP were thoroughly analyzed using the generalized gradient approximation of density functional theory and the plane-wave pseudopotential method. Our findings indicate that the structural, electronic, elastic, and mechanical properties of WRuP are in good agreement with experimental data, suggesting that this superconductor is both mechanically stable and ductile with strong metallic bonding. The band structure analysis reveals that WRuP behaves metallically, with the density of states primarily contributed by the d states of the transition metal atoms. Furthermore, the phonon band structure analysis demonstrates that WRuP is dynamically stable, with no imaginary phonon frequencies, and the estimated electron-phonon coupling constant (λ) is 0.69. According to our calculations using the Allen–Dynes formula, the superconducting transition temperature of WRuP is estimated to be 5.74 K, consistent with the experimental value of 5.5 K. These results collectively show that WRuP is a conventional phonon-mediated superconductor with strong electron-phonon coupling.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"629 ","pages":"Article 1354645"},"PeriodicalIF":1.3,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation and analysis of a superconducting switch based on Josephson array","authors":"Hai Wang ,&nbsp;Jiajun Chen ,&nbsp;Yifan Wu ,&nbsp;Wenqi Wu ,&nbsp;Zhidan Zhang ,&nbsp;Xiangyan Kong","doi":"10.1016/j.physc.2024.1354644","DOIUrl":"10.1016/j.physc.2024.1354644","url":null,"abstract":"<div><div>Superconducting transition edge sensors (TES) have been applied to a variety of astronomical detection systems. To improve their detection efficiency, superconducting switches are essential components in time-division multiplexing systems. However, flux-actuated superconducting switches have such problems as large area, high noise, and complex operation. This paper proposes a structure of non-hysteresis Josephson junction array with RL transmission unit to realize a superconducting switch. Firstly, based on the current equation of the Josephson junction, a PSPICE model of a superconducting switch was established. Then, the optimization design of a single junction switch transmitting a 100 MHz signal was analyzed. Finally, we analyzed how to suppress high-frequency noise when transmitting signals above 1 GHz. Since the signal of the Josephson junction array switch is directly read out by the SQUID, it has the advantage of reducing the switch area and operation complexity.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"629 ","pages":"Article 1354644"},"PeriodicalIF":1.3,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid vortex flux motion in GdBa2Cu3O7−d nanobridges","authors":"L.E. Díaz ,&nbsp;N. Haberkorn","doi":"10.1016/j.physc.2025.1354649","DOIUrl":"10.1016/j.physc.2025.1354649","url":null,"abstract":"<div><div>We report on the vortex dynamics of a GdBa₂Cu₃O_7−δ nanobridge through current-voltage measurements. The study is conducted on a sample with a length of 10 μm, a width of 0.62 μm, and a thickness of 80 nm, which was grown by sputtering and fabricated using a two-step process: first, optical lithography, followed by focused ion beam milling. The results show that the film exhibits a low critical current density but demonstrates high vortex flux motion. From the Larkin–Ovchinnikov instability, we extract velocities exceeding 10 km/s at low temperatures and fields around 0.4 T (with nearly 10 vortices crossing the bridge width) and approximately 3 km/s for fields around 5 T. These results are compared with recent publications reporting high vortex velocities.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"629 ","pages":"Article 1354649"},"PeriodicalIF":1.3,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Minimal surfaces & the intermediate state of type-I superconductors","authors":"Pavol Valko ,&nbsp;Thomas A. Girard","doi":"10.1016/j.physc.2024.1354641","DOIUrl":"10.1016/j.physc.2024.1354641","url":null,"abstract":"<div><div>The geometry of the intermediate state (IS) flux structures in type-I superconductors, observed during early stages of magnetic flux penetration induced by an externally applied perpendicular magnetic field, is analysed using the concept of minimal surfaces. This approach is based on the assumption that local free energy minimization, for each individual flux structure, dominates when the magnetic flux regions are sufficiently spatially separated; that is, when the global free energy minimization predicts very low periodicity in the intermediate state of the sample.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"629 ","pages":"Article 1354641"},"PeriodicalIF":1.3,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and characterization of YBCO superconducting thin films doped with BaHfO3 via the TFA-MOD technique for potential aerospace applications","authors":"Murat Bektas ,&nbsp;Isil Birlik ,&nbsp;Erdal Celik","doi":"10.1016/j.physc.2024.1354633","DOIUrl":"10.1016/j.physc.2024.1354633","url":null,"abstract":"<div><div>The study aims to improve the critical current density (<em>J_c</em>) and flux pinning of YBa₂Cu₃O_7-δ (YBCO) high-temperature superconducting films. The decline in <em>J_c</em> at high temperatures and magnetic fields is due to intrinsic crystalline anisotropy, thermal fluctuations, and lack of effective pinning centers. To tackle this, the study uses a novel approach by incorporating BaHfO₃ (BHO) nanostructures (dots, rods, or particles) as artificial pinning centers in YBCO films. The objective is to augment critical current density and enhance flux pinning properties using trifluoroacetates metal organic deposition method (TFA-MOD) on SrTiO₃ (STO) substrates, with a specific focus on applications in the aerospace industry. Characterization of YBCO solutions involves measuring contact angle, viscosity, and modulus. Thermal, structural, microstructural and superconducting properties of the films were scrutinized by Differential Thermal Analysis-Thermogravimetry (DTA-TG), Fourier Transform Infrared (FTIR), X-ray diffractometry (XRD), X-Ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) and Atomic Force Microscopy (AFM), Surface Profilometer (SP) and Physical Property Measurement System (PPMS). Rheological tests show viscosity decreases with temperature before stabilizing. Undoped YBCO exhibits good wetting on STO substrates. Heat treatment involves organic solvent removal and TFA decomposition, with FTIR and XRD analyses confirming decomposition of acetate complexes and strong c-axis texture. XPS results indicate consistent chemical compositions, while surface morphologies are flat and crack-free, with denser structures in BHO-doped films. Doping improves superconductivity up to a certain concentration, after which it decreases. Average film thickness is around 240 nm. Undoped YBCO films exhibit poor superconducting properties due to secondary phases, while BHO doping influences superconductivity, with an increase in critical current density up to a certain concentration, beyond which superconductivity is lost.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"629 ","pages":"Article 1354633"},"PeriodicalIF":1.3,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Superconducting DC busbar with low resistive joints for all-electric aircraft propulsion system","authors":"Gaurav Gautam ,&nbsp;Min Zhang ,&nbsp;Weijia Yuan ,&nbsp;Graeme Burt ,&nbsp;Daniel Malkin","doi":"10.1016/j.physc.2024.1354617","DOIUrl":"10.1016/j.physc.2024.1354617","url":null,"abstract":"<div><div>High-temperature superconductors (HTS) can carry high currents with almost zero loss when transmitting direct current (DC). Their compact size and lower weight make them suitable for the application of all-electric aircraft. However, the current carrying capability of a single HTS tape is limited to a few hundred amps; therefore, for high-current applications, multiple HTS tapes need to be connected in parallel. The flat geometry of HTS tape and its critical current (IC) dependence on strain complicate grouping them in parallel. Furthermore, the length of HTS tape is limited by its crystal structure, necessitating low-resistance joints for extended applications. A superconducting busbar design for high-current applications is developed and tested to address these challenges. The superconducting busbar is designed in a way that it helps to reduce the effect of the self-field on critical current and also ride through the fault events. Yttrium barium copper oxide (YBCO) tapes are used to develop the busbar prototype, tested against DC currents in a liquid nitrogen environment. Joint optimization is carried out to determine the required length for efficiently joining HTS tapes. Two busbar prototypes are developed with 180° and 90° joints to join 5 HTS tapes and tested in self-field. A joint resistance of 100 <em>n</em>Ω is measured at self-field for the 180° joint busbar, and 800 <em>n</em>Ω is measured for the 90° joint busbar. Both busbar prototypes are subjected to power cycling and thermal cycling to assess joint performance in self-field and any degradation of the joint electrical parameters during testing.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"627 ","pages":"Article 1354617"},"PeriodicalIF":1.3,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and experiment of superconducting Eddy current braking prototype device","authors":"Wenhua Dai ,&nbsp;Weibin Xi ,&nbsp;Chao Fang ,&nbsp;Jing Wei ,&nbsp;Shuangsong Du ,&nbsp;Rui Hu ,&nbsp;Zhengbao Yu","doi":"10.1016/j.physc.2024.1354619","DOIUrl":"10.1016/j.physc.2024.1354619","url":null,"abstract":"<div><div>An experimental superconducting eddy current braking prototype was designed, constructed and thoroughly evaluated. The components of the apparatus were accurately described, and heat leakage was calculated. The results showed that the heat leakage was 0.53 W at 5 K and 19.2 W at 40 K. The selected cryogenic system met the operational requirements of the apparatus. The fabrication process was outlined, and the apparatus was tested with the integrated cryogenic system. The device successfully cooled to the target temperature. The circular coil, carrying a current of 180 A, generated a braking force of 0.7 kN at a speed of 400 km/h, while the racetrack coil, at 50 A, produced 0.15 kN at the same speed. The experimental results were consistent with the analysis, demonstrating the successful operation of the prototype throughout the testing phase.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"629 ","pages":"Article 1354619"},"PeriodicalIF":1.3,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does the Meissner effect violate the second law of thermodynamics?","authors":"J.E. Hirsch","doi":"10.1016/j.physc.2024.1354618","DOIUrl":"10.1016/j.physc.2024.1354618","url":null,"abstract":"<div><div>In Entropy 24, 83 (2022) (Nikulov 2022), titled “The Law of Entropy Increase and the Meissner Effect”, its author Alexey Nikulov argues that the Meissner effect exhibited by type I superconductors violates the second law of thermodynamics. Contrary to this claim, I show that the Meissner effect is consistent with the second law of thermodynamics provided that a mechanism exists for the supercurrent to start and stop without generation of Joule heat. The theory of hole superconductivity provides such a mechanism, the conventional theory of superconductivity does not. It requires the existence of hole carriers in the normal state of the system.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"629 ","pages":"Article 1354618"},"PeriodicalIF":1.3,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comment on “Magnetic flux trapping in hydrogen-rich high-temperature superconductors” by V.S. Minkov, V. Ksenofontov, S.L. Bud’ko, E.F. Talantsev and M.I. Eremets, Nat. Phys. 19, 1293 (2023)","authors":"N. Zen","doi":"10.1016/j.physc.2024.1354614","DOIUrl":"10.1016/j.physc.2024.1354614","url":null,"abstract":"<div><div>In the paper, Minkov et al. (2023), Eremets et al. present experimental results for flux creep measurements using H₃S under high pressure in a diamond anvil cell, the pioneering material for the era of hydride superconductivity, with the aim of providing evidence that magnetic flux is trapped in H₃S under high pressure and that persistent currents are circulating there. Initially, it was thought that the measurements started immediately after switching off the applied magnetic field, as indicated by the labeling of the horizontal axis of Fig. 4c of Ref. Minkov et al. (2023). However, it was revealed in private communications by Eremets et al. to the author and in a later paper by Bud’ko et al. (2024) <span><span>[1]</span></span> that there was a large delay time in starting the flux creep measurements. If that is the case, the measurement period of <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span> s or <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>5</mn></mrow></msup></mrow></math></span> s as shown in Fig. 4c is too short to draw any conclusions about flux creep, or even to determine whether flux creep was being measured.</div></div>","PeriodicalId":20159,"journal":{"name":"Physica C-superconductivity and Its Applications","volume":"628 ","pages":"Article 1354614"},"PeriodicalIF":1.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}