engleski

Freezing of low energy excitations in charge density wave glasses

Thermally stimulated discharge current measurements were performed to study slow relaxation processes in two canonical charge density wave systems K0.3MoO3 and o-TaS3. Two relaxation processes were observed and characterized in each system, corroborating the results of dielectric spectroscopy. Our results are consistent with the scenario of the glass transition on the charge density wave superstructure level. In particular, the results directly prove the previously proposed criterion of charge density wave freezing based on the interplay of charge density wave pinning by impurities and screening by free carriers. In addition, we obtained new information on distribution of relaxation parameters, as well as on nonlinear dielectric response both below and above the threshold field for charge density wave sliding.

charge density waves ; glass transition ; thermally stimulated discharge

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