LOCAL MAGNETISM AND CRYSTAL FIELDS OF PR IN PRBA2CU3O7 STUDIED BY PR-141 NMR

We present the first study of the Pr-141 nuclear resonance in PrBa2Cu3 O7. In strong contrast to the current understanding of PrBa2CU3O7, We observe a small ordered Pr moment at low temperatures (0.017 mu(B)), o riented perpendicular to the c axis, and a temperature and field indep endent Van Vleck susceptibility below 10 K. We find a Gamma(1) ground state symmetry and a larger splitting of the quasitriplet than observe d in inelastic neutron scattering. We propose that the origin of the ( 1/2, 1/2, 0) Bragg peak in neutron diffraction is a ferromagnetic coup ling between the CuO2 planes of a bilayer induced by Pr.