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

By measuring the electric conductivity, dielectric susceptibility and thermally stimulated depolarization of the charge density wave system K0.3MoO3 we have found two relaxation processes in the temperature range between 100-10 K. The main relaxation process representing the CDW viscosity shows a critical slowing down behavior and disappears from the measured frequency window at about 28 K. The second one appears below 50 K and becomes the dominant relaxation below 30 K with a relaxation time decreasing with temperature slower than thermally activated, probably corresponding to tunneling between pinned CDW regions. The evidence for this interpretation comes from the temperature and frequency dependence of the conductivity. Together, this gives evidence for a glass-like behavior similar to chalcogenide glass semiconductors.