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

A Chroneos,M V Korobkov,A V Mazepulin,G Ya Khadzhai,I L Goulatis,R V Vovk

doi:10.1007/s10854-022-07977-5

Abstract

In the present work, we investigated the influence of high hydrostatic pressure up to 11 kbar on the conductivity in the basal ab-plane of medium-doped with praseodymium (x≈0.23) single-crystal Y1-xPrxBa2Cu3O7-δ samples. It was determined that, in contrast to the pure YBa2Cu3O7-δsamples with the optimal oxygen content, the application of high pressure leads to the formation of phase separation in the basal plane of Y0.77Pr0.23Ba2Cu3O7-δ single crystals. Possible mechanisms of the effect of Pr doping and high pressure on the two-step resistive transition to the superconducting state are discussed. It was determined that in the normal state, the conductivity is metallic and is limited by phonons scattering (Bloch-Grüneisen regime) and defects. The fluctuation conductivity is considered within the Lorentz-Doniach model. Hydrostatic pressure, accompanied by a decrease in anisotropy, leads to a decrease in the residual and phonon resistances. Debye temperature and coherence length are independent of pressure. The applicability of the McMillan formula in the presence of significant anisotropy is discussed.

Highlights

The use of high-pressure technologies to study the critical characteristics of high-temperature superconductor (HTSC) materials continues to be one of the most promising experimental techniques that allow checking the adequacy of theoretical models and finding empirical ways to improve their electrical transport characteristics and increase critical parameters [1, 2]
In previous work [26, 27], we studied the effect of high hydrostatic pressure up to 17 kbar on the resistive characteristics of poorly doped praseodymium (x&0.05) and excess conductivity (x&0.23) single-crystal Y1-xPrxBa2Cu3O7-d samples
The main contribution to the resistivity of the Y0.77Pr0.23Ba2Cu3O7-d single crystal is made by intraband scattering (μ T 5) and residual resistivity

Summary

Introduction

The use of high-pressure technologies to study the critical characteristics of high-temperature superconductor (HTSC) materials continues to be one of the most promising experimental techniques that allow checking the adequacy of theoretical models and finding empirical ways to improve their electrical transport characteristics and increase critical parameters [1, 2]. This is important, given that, despite the 35-year history of intensive theoretical and experimental research (from the discovery of HTSC in 1986 [3]), it is not possible to overcome the threshold of 200 K of the critical temperature (Tc) [4, 5]. In the Y1-xPrxBa2Cu3O7-d compounds with the optimal oxygen content [15, 16], the so-called nonequilibrium state does not arise, which in pure oxygen-deficient YBa2Cu3O7-d samples can be quite induced by a jump in temperature, aging [17, 18] or high-pressure applications [19, 20]

Methods

Results

Conclusion