Study of Resistive Superconducting Transition of Bulk $(Bi_{0.6}Pb_{0.4})_2Sr_2Ca_2Cu_{3}O_{x}$

The temperature widths of the resistive transition as well as the thermal fluctuations of bulk $(Bi_{0.6}Pb_{0.4})_2Sr_2Ca_2Cu_{3}O_{x}$ superconductor with $T_{c,50%}$ = 107.1 K were studied. The applied magnetic field widens the resistive transition according to the following formula: ΔT = $CH^{m} + ΔT_{0}$. The value of exponent m = 0.44 suggests that there is strong pining of vortices, especially at lower temperatures. The critical exponents λ of the conductivity were calculated using the following equation: Δσ = $Kε^{-λ}$, with the $λ_1$ = 1.75 close to the zero critical temperature and $λ_2$ = 3.77 at higher temperatures. These values were discussed within the available theoretical models.