Transverse-and zero-field μSR investigation of magnetism and superconductivity in (Y1-xPrx)Ba2Cu3O7

Zero-field muon-spin-rotation (μSR) measurements on (Y1-xPrx)Ba2Cu3O7 [x=1.0, 0.8, 0.6, and 0.54] show evidence for antiferromagnetic ordering of the Cu moments within the Cu-O planes, with Néel temperatures 285, 220, 35. 30 and 20 K, respectively. For x=1.0 the local muon magnetic field is ≈16 mT, but decreases to ≈12 mT at 17K, due to additional magnetic ordering. The zero-field data, in conjunction with transport data, allow construction of a complete phase diagram for this system. Transverse-field (1 kOe) μSR data for x=0.2 (Tc=75 K) show that the muon depolarization is determined primarily by the Cu nuclear moments for T>Tc, and by the vortex state for T<Tc. Fitting the superconducting-state data to a BCS model yields an extrapolated zero-temperature magnetic penetration depth of 2170 Å. © 1990 J.C. Baltzer A.G. Scientific Publishing Company.