ON THE ELECTRICAL-CONDUCTIVITY OF PR-RE-BA-CU-O (RE = ER, YB, LU, TM) COMPOUNDS IN ORTHORHOMBIC PHASE

Experimental results showing the temperature dependence of the conductivity of a variety of Pr-RE-Ba-Cu-O (RE = Er, Yb, Lu, and Tm) compounds are presented. The semiconducting behavior of the conductivity observed is analysed using ln sigma approximately T-2/5 and ln sigma approximately T-1/4 laws suggested, using the small-polaron hopping model by Triberis et al., for the high- and low-temperature regime, respectively. The agreement of the experimental data with these models is very satisfactory, giving a meaningful interpretation of the transport mechanism of these materials.