next up previous contents
Next: 5.1 Introduction Up: Kenji Kojima's Ph.D. Thesis Previous: 4.4 Summary

% latex2html id marker 10653

5 Haldane system

  This chapter contains our $\mu$SR and susceptibility measurements for the Haldane material, Y2BaNiO5. First, in the nominally pure system, the absence of magnetic order was confirmed with the ZF/LF-$\mu$SR measurements down to 100 mK. Second, the effects of charge doping (Y3+$\rightarrow$Ca2+) and vacancy doping (Ni2+$\rightarrow$Mg2+) were investigated. The charge doped system exhibited a spin-glass like behavior in the susceptibility, while our $\mu$SR measurements revealed unconventional spin dynamics in the milli-Kelvin regime. In the vacancy doped systems, the non-magnetic ground state survives.