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تسجيل مستخدم جديدScaling behavior of current- voltage characteristics of Y(1-x)CaxBa2Cu3O(7-{delta}) polycrystalline samples
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I-V characteristics of polycrystalline Y(1-x)CaxBa2Cu3O(7-{delta}) 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 Y0.8Ca0.2Ba2Cu3O(7-{delta}). The static exponent { u} has been determined from {rho} vs. T dependence at given magnetic field. The critical exponents are field independent with one only exception ({ u} - for Y0.975Ca0.025Ba2Cu3O(7-{delta}) sample). This is connected with the special interrelation between the vortex correlation length, {xi}, and intervortex spacing {alpha} ({xi} leq {alpha}) at all magnetic fields above Tg for this sample and its better pinning.
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