Metal-insulator transition in single crystals Y1–zPrzBa2Cu3O7–δ
G. Ya. Khadzhai1, A. L. Solovjov1,2,4, N. G. Panchenko3, M. R. Vovk1, and R. V. Vovk1,3
1V. N. Karazin Kharkiv National University, Kharkiv 61077, Ukraine
3Ukrainian State University of Railway Transport, Kharkiv 61050, Ukraine
Received February 20, 2022, published online May 20, 2022
The aim was to conduct comparative studies of the evolution of conductivity along and across the base ab plane in Y1–zPrzBa2Cu3O7–δ single crystals at different degrees of praseodymium doping in a wide range of concentrations 0 ≤ z ≤ 0.5. It is established that the increase in the degree of praseodymium doping in samples Y1–zPrzBa2Cu3O7–δ leads to increased effects of localization and implementation in the system of metal–insulator type transition, which always precedes the superconducting transition. Increasing the concentration of praseodymium leads to a significant shift in the beginning of the metal–insulator transition at the low temperature region.
Key words:  high-temperature superconductivity, metal-insulator transition, doping, Y1–zPrzBa2Cu3O7–δ single crystals, localization effects.