Electronic properties of ${\mathrm{Ba}}_2{\mathrm{Y}}_{1-x}{\mathrm{Pr}}_x{\mathrm{Cu}}_3{\mathrm{O}}_{7-\delta }$

Measurement of the Hall coefficient in the ${\mathrm{Ba}}_2{\mathrm{Y}}_{1-x}{\mathrm{Pr}}_x{\mathrm{Cu}}_3{\mathrm{O}}_{7-\delta }$ system has revealed that an increase in Pr concentration reduces the Hall carrier number ($\frac{1}{{\mathrm{eR}}_H}$) and its strong temperature dependence. The Cu formal valence calculated from the Pr valence, which has been determined to be ∼+3.5, shows a weakly decreasing dependence on Pr concentration. $T_c$ shows a stronger dependence on the Hall carrier number and the Cu-O formal valence than in the oxygen-depleted ${\mathrm{Ba}}_2{\mathrm{YCu}}_3{\mathrm{O}}_{7-\delta }$ system. The persistence of the chain band explains this observed difference, suggesting that the actual Cu-O valence dependence of the 90-K superconductor is stronger than that of the 40-K superconductor.