Glass-like behavior in the CDW state of the quasi-one-dimensional conductor K0.3MoO3

By measuring the electric conductivity, dielectric susceptibility and therm ally stimulated depolarization of the charge density wave system K0.3MoO3 w e have found two relaxation processes in the temperature range between 100- 10 K. The main relaxation process representing the CDW viscosity shows a cr itical slowing down behavior and disappears from the measured frequency win dow at about 28 K. The second one appears below 50 K and becomes the domina nt relaxation below 30 K with a relaxation time decreasing with temperature slower than thermally activated, probably corresponding to tunneling betwe en pinned CDW regions. The evidence for this interpretation comes from the temperature and frequency dependence of the conductivity. Together, this gi ves evidence for a glass-like behavior similar to chalcogenide glass semico nductors.