Muon depolarization and magnetic field penetration depth in superconductingGdBa2Cu3Ox

Abstract

Positive muon spin-rotation ($\mu \mathrm{SR}$) measurements on $\mathrm{Gd}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_x \left(x\approx 7\right)$ have been conducted in the temperature interval 5.8-300 K. A temperature-dependent relaxation, attributable to Korringa relaxation of the Gd ion, as well as vortex-state relaxation are observed. Magnetic field penetration depths of approximately 1550 and 1900 Å (two samples) are extracted from the data. Two muon stopping sites exist for $T\le 80$ K, one being associated with normal regions of the sample and the other with superconducting regions.