Correlation of Tc with Hole Concentration in Copper-Oxide Superconductors; Hall Effect Measurement in Nd1+xBa2-xCu3O7-δ

Abstract
Hole concentration compensation effect in Nd1+x Ba2-x Cu3O7-δ and a simple correlation of T c with the hole concentration in copper-oxide-type superconductors, proposed in a previous paper by the present authors, have been supported by the Hall effect measurement. The effective hole concentration p H (=1/R H e) deduced from the Hall coefficient, R H, decreases with increasing x. The plot of T c against p H obtained in the present system is very similar to that of oxygen-doped YBa2Cu3O7-δ in spite of that the two systems differ in the oxygen content, δ. This suggests that the hole concentration is a more essential parameter than the oxygen content δ, in determining the superconductivity of copper-oxide superconductors.