Analysis of possible causes of suppression of superconductivity in Y1-χPrχBa2Cu3Oy

Temperature dependencies of thermo-electromotive force coefficient in the Y1-χPrχBa2Cu3Oy (χ = 0 - 0.6) samples are studied. The basic parameters of charge carriers system are determined on the basis of analysis of these dependences within the range of a narrow conducting zone and their change with growth of praseodymium content is analyzed. It is found that the χ increase leads to very small growth of the zine filling rate with electrons and to significant expansion of the conducting zone, accompanied by strong localization of charge carriers. On the basis of comparative analysis the conclusion is made that the praseodymium valency in the Y1-χPrχBa2Cu3Oy system is very close to 3+ value