ISSN:
1434-6036
Keywords:
PACS. 72.15.Nj Collective modes (e.g., in one-dimensional conductors) – 71.45.Lr Charge-density-wave-systems – 77.22.Gm Dielectric loss and relaxation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract: We report a detailed characterization of an unique 2- and 4-fold commensurate charge density wave (CDW) state in single crystals of the organic conductor (2.5(OCH3)2DCNQI)2Li by means of low-frequency (0.1 Hz-1 MHz) dielectric spectroscopy. We show that in addition to the narrow Debye-like relaxation mode of strength Δɛ≈ 10 7 with Arrhenius-like resistive decay, associated with long wavelength phason excitations, a new mode of weaker strength Δɛ≈ 10 6 appears below 40 K and broadens with decrease in temperature. Below 25 K the mean relaxation time of the new mode saturates, whereas the Debye mode continues gradual slowing down with weaker temperature dependence, again similar to the DC conductivity. We attribute the new process to short wavelength CDW excitations that become dominant once the free carrier density is substantially reduced at low temperatures.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s100510170111
