Influence of Uniform Compression on the Temperature Dependence of the Pseudogap of Medium-Praseodymium-Doped Y1−xPrxBa2Cu3O7−δ Single Crystals

Abstract

The effect of high pressure on the conductivity in the basal plane of HTSC single crystals of Y0.77Pr0.23Ba2Cu3O7−δ is investigated. It has been established that the excess conductivity, Δσ(T), of these single crystals in a wide temperature range Tf < T < T* can be described by an exponential temperature dependence. The description of the excess conductivity using the relation Δσ ~ (1 − T/T*)exp(Δ*ab/T) can be interpreted in terms of the mean-field theory, where T* is represented as the temperature pseudogap opening, and the temperature dependence of the pseudogap (PG) is satisfactorily described in the framework of the BCS-BEC crossover theory. An increase in the applied pressure leads to the effect of narrowing the temperature interval for the realization of the PG-regime, thereby expanding the region of the linear dependence ρ(T) in the ab-plane.

Effect of high pressure on temperature dependences of the resistivity in the ab-plane of Y0.77Pr0.23Ba2Cu3O7-δ single crystals

“…This procedure made it possible to obtain a contact resistance of less than one Ohm and to carry out resistive measurements at transport currents up to 10 mA in the abplane. Hydrostatic pressure was created in a pistoncylinder multiplier [26,27]. The pressure was determined using a manganin manometer, and the temperature was determined with a copper-constantan thermocouple mounted on the outer surface of the chamber at the level of the sample position.…”