JOURNAL OF LOW TEMPERATURE PHYSICS, cilt.105, ss.975-980, 1996 (SCI-Expanded)
Voltage-current characteristics of YBCO superconductor was studied under magnetic field up to 0.4 T at different temperatures below T-c. The critical temperature decreases and the transition width broadens under magnetic field. V-I data below T-c were fitted to a power law expression V similar to I-beta(T,I-B) in which beta(T,B) is found to decrease with increase of magnetic field and temperature, gradually approaching unity as T approaches T-c, being independent of magnetic field. Similarly beta(T,B) approaches unity as magnetic field increases being independent of temperature.