Superconducting magnetization and pressure effect on Tc in the infinite-layer high-Tc superconductors

High-resolution neutron powder diffraction experiments and magnetization measurements were performed for a series of the electron-doped infinite-layer high-temperature superconductors Sr1-xRxCuO2 (R = La, Pr; 0.07 less than or equal to x less than or equal to 0.15). Zero-field-cooled magnetization measurements performed for the powder Sr0.9Pr0.1CuO2 sample under hydrostatic pressure up to 0.5 GPa at a magnetic field of 0.005 T revealed a downward shift of the onset temperature T-c(onset) of the diamagnetic response described by the pressure derivative dT(c)(onsel)/dp = -(0.75 +/- 0.30) K/GPa. By measuring the reversible superconducting magnetization for the powder aligned Sr0.9Pr0.1CuO2 sample at high fields 1 less than or equal to mu(0)H less than or equal to 5 T, we found that the 3D-lowest-Landau-level approximation is a good description of fluctuation magnetization, if one takes into the curvature of the critical line B-c2 (T) proportional to\T - T-c\(4/3). (C) 2003 Elsevier B.V. All rights reserved.