Magnetic properties and spin dynamics in hole-doped S=1 AF chain: (super89)Y NMR and susceptibility in Y(sub2-x)CaxBaNiO(sub5)

The compound Y(sub2)BaNiO(sub5) (YBNO) is distinguished by the presence of weakly coupled chains of interacting Ni(super2+) ions. YBNO is of interest as the relatively high gap and small values of the anistropy terms D and E enable the study of the Haldane ground state in a wide temperature range. The magnetic susceptibility X, (super89)Y shift K, T(sub1) and T(sub2) measurements in Y(sub2-x)CaxBaNiO(sub5), is presented. (super89)Y relaxation rates suggest that holes induce low-energy excitations with efficient spectral density.