The magnetoresistance of a (Bi,Pb)2Sr2Ca2Cu3O10+y Ag sheathed tape was measured in the temperature range 15 K ≤ T ≤ 120 K and magnetic field B ≤ 15 T applied perpendicular to the broader surface of tape. Throughout the explored field range, the onset of resistivity shows Arrhenius behaviour ρ ∝ exp(−U∗(1 − T /Tcs)/kBT B0.5) where U∗ is the sample dependent constant, and Tcs is the temperature somewhat higher than the temperature of the resistivity onset. The observed resistance variation can be attributed to a thermally activated flux flow in a highly viscous vortex-liquid regime characterized by a plastic deformation of vortices. Experimentally determined resistive irreversibility line Birr vs. Tirr follows the power-law dependence Birr(Tirr) ∝ (Tcs/Tirr − 1)2 which can be derived from the exponential behaviour of resistivity. Our Birr(Tirr) data can also be fitted by the combination of the Josephson coupling model and depinning of pancake vortices. This fit provides very reasonable values for Bc2, Bc1, Bc, ξab and λab of Bi2223 compound, and removes the unphysical divergence of Birr(T → 0)
resulting from the above power-law fit.Mjerili smo magnetootpor (Bi,Pb)2Sr2Ca2Cu3O10+y vrpce obložene srebrom za temperature 15 K ≤ T ≤ 120 K i u magnetskim poljima B ≤ 15 T okomitim na širu plohu vrpce. U svim poljima početak otpora pokazuje Arrheniusovo ponašanje ρ ∝ exp(−U∗(1 − T /Tcs)/kBT B0.5), gdje je U∗ konstanta ovisna o uzorku, a Tcs je temperatura nešto viša od temperature pojave otpora. Primijetili smo da se ovisnost otpornosti može pripisati termički pobuđenom tečenju toka u jako viskoznom području tekućine magnetskih vrtloga karakteriziranom plastičnim deformacijama magnetskih vrtloga. Eksperimentalno određena otporna linija ireverzibilnosti Birr(Tirr) slijedi potencijsku ovisnost Birr(Tirr) ∝ (Tcs/Tirr − 1)2 koja se može izvesti iz eksponencijalnoe ovisnosti otpornosti. Naši Birr(Tirr) podaci isto tako mogu se prilagoditi modelu Josephsonovog vezanja i otpinjanja magnetskih vrtloga–palačinki. Ova prilagodba daje razumne vrijednosti parametara Bc2, Bc1, Bc, ξab i λab Bi2223 spoja, te uklanja nefizikalnu divergenciju Birr(T → 0) koja se dobiva iz potencijske ovisnosti
