I-V characteristics of polycrystalline Y1-xCaxBa2Cu3O7-δ samples (x=0.025 and 0.20) have been measured at
different temperatures and magnetic fields in the range 0.1 T-6.9 T. The scaling behavior has been established for both
samples at all magnetic fields. The dynamic exponent z displays some morphology dependence with higher value for
small grain size sample Y0.8Ca0.2Ba2Cu3O7-δ. The static exponent ν has been determined from ρ vs. T dependence at given
magnetic field. The critical exponents are field independent with one only exception (ν - for Y0.975Ca0.025Ba2Cu3O7-δ
sample). This is connected with the special interrelation between the vortex correlation length, ξ, and intervortex spacing
α (ξ ≤ α) at all magnetic fields above Tg for this sample and its better pinning.