Scaling of the transport properties in the Y1-yPryBa2Cu3Ox system - art. no. 184425

We report on the temperature dependent resistivity of YBa2Cu3Ox and (Y0.6Pr 0.4)Ba2Cu3Ox epitaxial thin films, measured in pulsed magnetic fields up to 50 T The zero-field rho (T) data for various levels of hole doping p can b e scaled onto one single universal curve by using a linear transformation o f both temperature and resistivity. This universal curve exhibits a linear rho (T) at high temperatures T > T* (region I) and a superlinear rho (T) at intermediate temperatures T-MI < T < T* (region II). The ground state in t he low temperature region T < T-MI (region III) is masked by the presence o f superconductivity below T-c, but is accessible in high magnetic fields. T he high field measurements reveal that YBa2Cu3Ox (for x < 6.8) and (Y0.6Pr0 .4)Ba2Cu3Ox (for all levels of oxygen content) have an "insulatinglike" gro und state at low temperatures and that the universal scaling may be extende d to region III. The existence of a universal rho (T) curve indicates that the same mechanisms are dominating the scattering of the charge carriers in these materials but with a different energy scale depending on the carrier concentration and/or the defect structure.