For citation: Gasumyants, V. E. (2020) The calcium effect on the thermopower, critical temperature and charge-carrier system parameters in the Y 0.75-x Ca x Pr 0.25 Ba 2 Cu 3 O y HTSC-system. Abstract. Superconducting properties and thermopower temperature dependences for two series of ceramic samples with Y 0.75-x Ca x Pr 0.25 Ba 2 Cu 3 O y (x = 0-0.25) compositions are experimentally investigated. Thermopower temperature dependences are analysed using the phenomenological narrow-band model.

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... e normal state energy spectrum and the charge-carrier system parameters including the Fermi level position are determined and the doping influence on their value is discussed. It is shown that the Fermi level position in Y 0.75-x Ca x Pr 0.25 Ba 2 Cu 3 O y samples is determined by its pinning inside a local peak in the density-of-states function formed due to increasing calcium content. The influence of the observed normal-state energy spectrum modification on the critical temperature in the studied system is discussed.