Muon spin relaxation in the spin-ring system Cu3WO6: Quasistatic spin freezing at 7.0 K

Quasistatic spin freezing is observed at T=7.0 K in the muon spin relaxation (μSR) measurements of polycrystalline Cu3WO6. This material has been widely considered to possess a nonmagnetic spin-singlet ground state based on the previous neutron scattering and susceptibility studies in which a spin gap was observed. Zn-doped Cu3-xZnxWO6 with x>0, however, exhibit no signature of spin freezing. The μSR results of Cu3-xZnxWO6 are similar to those of a charge-ordered system NaxV2O5. A few interpretations of the observed spin freezing will be presented.