Peculiarities of pseudogap in Y0.95Pr0.05Ba2Cu3O7-δ single crystals under pressure up to 1.7 GPa

The effect of hydrostatic pressure up to P = 1.7 GPa on the fluctuation conductivity sigma'(T) and pseudogap Delta*(T) in Y0.95Pr0.05Ba2Cu3O7-delta single crystal with critical temperature T-c = 85.2 K (at P = 0) was investigated. The application of pressure leads to the increase in T-c with dT(c)/dP = +1.82 K.GPa(-1) while the resistance decreases as dln rho(100 K)/dP = -(10.5 +/- 0.2) %.GPa(-1). Regardless of the pressure, in the temperature interval from T-c to T-0 (similar to 88 K at P = 0) the behaviour of sigma'(T) is well described by the Aslamazov - Larkin (AL - 3D) fluctuation theory, and above the T-0 by the Lawrence - Doniach theory (LD). The Maki-Thompson (MT - 2D) fluctuation contribution is not observed. This indicates the presence of structural defects in the sample induced by Pr. Here it is determined for the first time that when the pressure is applied to the Y1-xPrxBa2Cu3O7-delta single crystal, the pseudogap increases as dln Delta*/dP = 0.17 GPa(-1).