JOURNAL OF LOW TEMPERATURE PHYSICS, vol.105, pp.957-962, 1996 (SCI-Expanded)
The voltage-current characteristics of polycrystalline (Bi,Pb)(2)Sr2Ca2Cu3O10 superconductor were investigated at temperatures from 80 to 105 K under magnetic field up to 0.4 T. In magnetic field considerable broadening in the transition width occurs which depends on the processing conditions and microstructure of the sample. I-V data below T-c were fitted to a power law expression V similar to I-beta to obtain beta. We have found that beta decreases rather rapidly with increase of magnetic field and temperature, in low magnetic fields and at temperatures quite below T-c, respectively. Similar behavior was observed for the variation of the critical current as a function of temperature and magnetic field. The beta values are found to change linearly as a function of critical current at relatively law values of I-c.