Orientation dependence of the magnetic field distributions in large single crystals of YBa₂Cu₃O₇

We have analyzed transverse field μSR data taken for fields parallel to, 45° from, and 90° from the c-axis of large crystals of YBa2Cu3O7. For each orientation, the applied field was about 10 mT and in a μSR apparatus at TRIUMF. The crystals had significant green phase inclusions which pinned the vortices from very near the transition temperature of about 92 K. Four different fitting functions were applied. The last fitting function used an anisotropic field distribution developed by Daemen et al. which should be appropriate for our low-field case and gives greater freedom to the function. With this function we were able to obtain fits for all angles using a reasonable penetration depth in the ab plane (λab=0.14μm) and a reasonable mass asymmetry, Γ=30.