Investigation into superconducting Y-Ba-Cu-O films containing regions of weak superconductivity and biased at I ≫ [I.sub.C]/Stiprios I ≫ [I.sub.C] elektros sroves tankio pasiskirstymas plonuose Y-Ba-Cu-O sluoksniuose, turinciuose silpnojo superlaidumo sritis

Current distribution in Y[Ba.sub.2][Cu.sub.3][O.sub.7-x] superconducting thin film micro-bridges containing laser-written Π-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 [T.sub.c] 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 LWchannel from its edges towards the centre. As follows from current-voltage dependences, vortices start moving at I = [I.sub.c]. This current already satisfies condition [F.sub.L] ≫ [F.sub.p] (where [F.sub.p]--is pinning force in the film). Our results confirm that coherent vortex motion in the channel holds even at high biasing current when I ~ 200[I.sub.c]. 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. Keywords: superconductors, thin films, critical current, magnetic vortex, superconducting channel, pinning force, Lorentz force. Nagrinejamas elektros sroves pasiskirstymas Y[Ba.sub.2][Cu.sub.3][O.sub.7-x] superlaidininko plonuose sluoksniuose, kuriuose lazerio spinduliu suformuoti Π formos sukuriu kanalai. Superlaidziajame darinyje atsiradus sukuriu kanalui, sroves tankis lokaliose darinio vietose gali skirtis 5 ir daugiau kartu, priklausomai nuo kanalo geometrijos. Darbe eksperimentiskai nustatyta, kad Abrikosovo magnetiniu sukuriu koherentinis judejimas sukuriu kanale siaurame temperaturu ruoze nuo 85,1 K iki 90,2 K prasideda superlaidziuoju dariniu tekant I ~ [I.sub.c] ir islieka iki ypac stipriu sroviu I > [200I.sup.1st step]. Cia [I.sup.1st step]--sroves stipris, kuriam esant sukuriu kanale vyksta koherentinis sukuriu judejimas, o [I.sub.c]--kritine superlaidininko srove. Koherentinis sukuriu judeji