Investigation of Density and Velocity of Abrikosov Vortices in YBa2Cu3O7–x Superconducting Thin Films with a Laser-Written Channel for Easy Vortex Motion

1970 ◽  
Vol 17 (2) ◽  
pp. 180-185
Author(s):  
Lina STEPONAVICIENE ◽  
Jonas SULCAS ◽  
Arturas JUKNA ◽  
Valentina PLAUSINAITIENE ◽  
Adulfas ABRUTIS ◽  
...  
Keyword(s):  
Vortex Motion ◽  
Limited Range ◽  
Coherent Motion ◽  
Superconducting Transition ◽  
Magnetic Vortices ◽  
Current Voltage ◽  
Coherent Vortex ◽  
Current Voltage Characteristics ◽  
Abrikosov Vortices

The 0.3-mm-thick, 50-mm-wide and 100-mm-long YBa2Cu3O7-x superconducting bridges with a laser-written, single, Π-shaped channel have been investigated by means of electronic transport measurements at temperatures below the onset of the bridge's superconducting transition temperature. Our results demonstrate that the coherent vortex motion confined in the P-shaped channel can be used for determination of both the density and velocity of Abrikosov magnetic vortices in the channel. The coherent motion of Abrikosov vortices expresses itself as Josephson-like voltage steps, observed on the current-voltage characteristics of our microbridges, measured at zero external magnetic field, in a limited range of temperatures and bias currents. The steps' amplitude corresponds to the entrance of an additional vortex-antivortex pair into the channel's area and change in the vortex velocity. This amplitude also affects the increase of the Lorentz force for energy dissipative drift of the magnetic flux in the channel, but it does not increase, however, with the increase of the biasing current. We present and discuss the results of experimentally measured and calculated energy dissipation, which originated from variations in the vortex density and velocity when the vortices are moving along the channel of the superconducting bridge.http://dx.doi.org/10.5755/j01.ms.17.2.489

scholarly journals INVESTIGATION INTO SUPERCONDUCTING Y-BA-CU-O FILMS CONTAINING REGIONS OF WEAK SUPERCONDUCTIVITY AND BIASED AT I >> IC / STIPRIOS I >> IC ELEKTROS SROVĖS TANKIO PASISKIRSTYMAS PLONUOSE Y-BA-CU-O SLUOKSNIUOSE, TURINČIUOSE SILPNOJO SUPERLAIDUMO SRITIS

2012 ◽  
Vol 3 (6) ◽  
pp. 101-104
Author(s):  
Jonas Šulcas ◽  
Artūras Jukna
Keyword(s):  
Narrow Range ◽  
Vortex Motion ◽  
Pinning Force ◽  
Superconducting Thin Film ◽  
Magnetic Vortices ◽  
Superconducting Device ◽  
Current Voltage ◽  
Coherent Vortex ◽  
Current Dissipation ◽  
Critical Temperature Tc

Current distribution in YBa2Cu3O7-x superconducting thin film micro-bridges containing laser–written -shaped channel for easy vortex motion have been investigated in a narrow range of temperatures ranging from 85.7 to 90.2 K, which are below the critical temperature Tc of the material. In the range of the before mentioned temperatures the current-self magnetic field produced, Abrikosov magnetic vortices/anti-vortices appear in the partially deoxygenated (x ~ 0.2) channel and move coherently identifying itself as Josephson–like voltage “steps” in nonlinear current–voltage dependences. Bias current creates Lorentz force FL, pushing vortices along the LW-channel from its edges towards the centre. As follows from current-voltage dependences, vortices start moving at I = Ic. This current already satisfies condition FL >> Fp (where Fp – is pinning force in the film). Our results confirm that coherent vortex motion in the channel holds even at high biasing current when I ~ 200Ic. However, at these biasing currents, the width of voltage steps appears to be shorter than at lower current. This phenomenon has been explained by means of the onset of additional vortex motion in the laser untreated regions of the superconducting device. These regions are located in between the Π-shaped channel for easy vortex motion. Our results also demonstrate the possibility of investigating the electric properties of the mixed state superconductor by means of current dissipation due to the onset of coherent vortex motion. Santrauka Nagrinėjamas elektros srovės pasiskirstymas YBa2Cu3O7-x superlaidininko plonuose sluoksniuose, kuriuose lazerio spinduliu suformuoti Π formos sūkurių kanalai. Superlaidžiajame darinyje atsiradus sūkurių kanalui, srovės tankis lokaliose darinio vietose gali skirtis 5 ir daugiau kartų, priklausomai nuo kanalo geometrijos. Darbe eksperimentiškai nustatyta, kad Abrikosovo magnetinių sūkurių koherentinis judėjimas sūkurių kanale siaurame temperatūrų ruože nuo 85,1 K iki 90,2 K prasideda superlaidžiuoju dariniu tekant I ~ Ic ir išlieka iki ypač stiprių srovių I > 200I1st step. Čia I1st step – srovės stipris, kuriam esant sūkurių kanale vyksta koherentinis sūkurių judėjimas, o Ic – kritinė superlaidininko srovė. Koherentinis sūkurių judėjimas kanalo srityje eksperimentuose pasireiškia darinių voltamperinėse charakteristikose elektros įtampos „laipteliais“, kurių aukštis beveik nepriklauso nuo dariniu tekančios srovės stiprio. Eksperimentiniai rezultatai paaiškinti koherentinio sūkurių judėjimo ypatumais Π formos sūkurių kanalu.

scholarly journals COHERENT VORTEX MOTION IN YBA2CU3O7-Z SUPERCONDUCTING THIN FILMS CONTAINING Π-SHAPED CHANNEL FOR EASY VORTEX MOTION BIASED AT I ~ IC / MAGNETINIŲ SŪKURIŲ KOHERENTINIO JUDĖJIMO YBA2CU3O7-X SUPERLAIDŽIUOSIUOSE PLONUOSIUOSE SLUOKSNIUOSE SU LAZERIU SUFORMUOTU

2012 ◽  
Vol 3 (6) ◽  
pp. 105-110
Author(s):  
Lina Steponavičienė ◽  
Artūras Jukna
Keyword(s):  
Oxygen Vacancies ◽  
Narrow Range ◽  
Vortex Motion ◽  
Bias Current ◽  
Pinning Force ◽  
Superconducting Thin Films ◽  
Magnetic Vortices ◽  
Current Voltage ◽  
Coherent Vortex ◽  
Critical Temperature Tc

The current vs. voltage dependences of YBa2Cu3O7-x superconducting microbridges containing laser–written (LW) -shaped channel for easy vortex motion have been investigated in a narrow range of temperatures ranging from 87.3 to 88.6 K that are still below the critical temperature Tc of the material. In the range of the before mentioned temperatures the current-self magnetic field produced, Abrikosov magnetic vortices/anti-vortices appear in the partially deoxygenated (x ~ 0.2) channel and move coherently identifying itself as Josephson–like voltage “steps” in nonlinear current–voltage dependences. Bias current creates Lorentz force FL, pushing vortices along the LW-channel from its edges towards the centre. As follows from current-voltage dependences, vortices start moving at I = Ic. This current satisfies condition FL >> Fp (where Fp – is pinning force in the film). Our results confirm that oxygen vacancies in the channel area decrease the pinning force of screw-dislocations and make the channel of uniform pinning. Then, even at I = Ic, Abrikosov magnetic vortices create a spontaneous channel in the deoxygenated channel of the superconducting microbridge and start moving coherently. Santrauka Darbe nagrinėjami silpnai tarpusavyje sąveikaujančių Abrikosovo magnetinių sūkurių judėjimo ypatumai 0,3 mm storio, 100 mm ilgio ir 50 mm pločio YBa2Cu3O7–xsuperlaidžiuosiuose dariniuose, turinčiuose iš dalies deguonimi nuskurdintą Π formos Abrikosovo magnetinių sūkurių kanalą. Sūkurių kanalas superlaidžiajame darinyje sudarytas sufokusuotu į 5 mm skersmens dėmę lazerio spinduliu. Šviesos poveikiu modifikuotame superlaidžiojo darinio kanale (x < 0,2) atsirado papildomi sūkurių prieraišos centrai (deguonies vakansijos), kurių kuriama sūkurių prieraišos jėga Fp sumažino stiprių prieraišos centrų kuriamą prieraišos jėgą ir sukūrė palankias sąlygas Abrikosovo magnetinių sūkurių judėjimui, dariniu tekant srovei, kurios tankis keliomis eilėmis mažesnis už šviesa nemodifikuoto superlaidininko dalies kritinį srovės tankį. Atliktų tyrimų rezultatai rodo, kad koherentinis Abrikosovo magnetinių sūkurių judėjimas superlaidininke, eksperimentuose pasireiškiantis įtampos laipteliais voltamperinėje darinio charakteristikoje, gali atsirasti esant FL >> Fp netgi tuomet, kai sūkurių kanalas nėra visiškai užpildytas Abrikosovo magnetiniais sūkuriais, dėl ko sūkuriai silpnai sąveikauja tarpusavyje.

scholarly journals Исследование критической температуры T-=SUB=-c-=/SUB=- гомофазных сверхпроводников (Bi-=SUB=-1.7-=/SUB=-Pb-=SUB=-0.3-=/SUB=-Sr-=SUB=-2-=/SUB=-Ca-=SUB=-(n-1)-=/SUB=-Cu-=SUB=-n-=/SUB=- O-=SUB=-y-=/SUB=- (n=3, 4, 5) и вольт-амперных характеристик сэндвич-пар полупроводник InP-сверхпроводник Bi/Pb (2223, 2234, 2245)

2019 ◽  
Vol 89 (4) ◽  
pp. 583
Author(s):  
Д.Д. Гуламова ◽  
А.В. Каримов ◽  
Д.Г. Чигвинадзе ◽  
С.М. Ашимов ◽  
О.В. Маградзе ◽  
...  
Keyword(s):  
Single Phase ◽  
Nominal Composition ◽  
Superconducting Transition ◽  
Critical Temperatures ◽  
Current Voltage ◽  
Anisotropic Superconductors ◽  
Bismuth Cuprates ◽  
Current Voltage Characteristics ◽  
The Relationship

AbstractThe electrophysical properties of semiconductor–superconductor sandwich pairs (InP–Bi/Pb 2223, 2234, 2245) are investigated, in which homophase superconductors based on bismuth cuprates with high reproducible critical temperatures of superconducting transition T _ c = 107–180 K are used. The advantage of melt solar technology for obtaining superconducting materials is demonstrated. The microstructure and phase composition of strongly anisotropic superconductors with nominal composition Bi_1.7Pb_0.3Sr_2Ca_( n _– 1)Cu_ n O_ y ( n = 3, 4, 5) are researched. A technique of experimental determination of superconducting transition critical temperatures T _ c in single-phase and homophase HTSC samples is presented. The current–voltage characteristics of InP–Bi/Pb pairs are investigated. The relationship between the electrical resistance of sandwich pairs and superconductor critical temperature T _ c is established.

Resistive Width of Superconducting Transition in Titanium Nitride Thin Film

2011 ◽  
Vol 6 (2) ◽  
pp. 50-56
Author(s):  
Svetlana V. Postolova ◽  
Alexey Yu. Mironov ◽  
Tatyana I. Baturina
Keyword(s):  
Transition Temperature ◽  
Titanium Nitride ◽  
Electron Interaction ◽  
Nitride Film ◽  
Superconducting Transition ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Superconducting Fluctuations ◽  
Width Of Superconducting Transition ◽  
Titanium Nitride Film

The transition to the superconducting state of the ultrathin (5 nm thick) titanium nitride film was studied. It is found that the nonmonotonic temperature dependence of the resistance, R(T), is a consequence of competition between the contributions to conductivity from quantum corrections stemming from the electron-electron interaction in the diffusion and Cooper channels. It is shown that the appreciable decrease in the resistance at T > Tc (Tc is the superconducting transition temperature) results from the superconducting fluctuations. We present the results of the analysis of low-temperature (T < Tc ) current-voltage characteristics V(I). It is found that they follow the power-law behavior V∝ I α(T) , with α(T) increasing rapidly with the decreasing temperature. The Berezinskii-Kosterlitz-Thouless transition temperature, TBKT, and width of the superconducting transition ∆T = Tc − TБКТ were determined

scholarly journals Nonlinear Response of a Superconductor of the Bi-Sr-Ca-Cu-O System to an Alternating Magnetic Field in the Superconducting Transition Temperature Range

2018 ◽  
Vol 185 ◽  
pp. 08005
Author(s):  
Alexander Sergeev ◽  
Igor Golev ◽  
Victoria Gvozdevskaya ◽  
Anastasia Barkalova
Keyword(s):  
Magnetic Field ◽  
Nonlinear Response ◽  
Alternating Magnetic Field ◽  
Resistive State ◽  
Superconducting Transition ◽  
Critical Temperatures ◽  
Temperature Range ◽  
Nonlinear Properties ◽  
Current Voltage ◽  
Current Voltage Characteristics

The nonlinear response of the superconductor of the Bi-Sr-Ca-Cu-O system in the temperature range of the superconducting transition under the action of a harmonic alternating magnetic field is experimentally studied. For multiphase superconductors having in their volume regions with distinct critical temperatures, the effect of odd harmonics in the response signal is observed. The contribution of crystallites and the system of weak bonds between the crystallites in the nonlinear response is singled out. It was found that the nonlinear properties of the investigated samples in the resistive state are determined mainly by the nonlinear current-voltage characteristics of the system of weak bonds between the crystallites.

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