engleski

Tuning charge density wave glass transition by introducing lattice disorder

Probing charge density wave system (CDW) o-TaS3 with dielectric spectroscopy reveals two processes determined by the CDW phase dynamics, one of which (-process) freezes at finite glass transition temperature TG at which there is less then one free carrier per phase coherence domain [1]. Irradiating the samples by 2 MeV protons we introduced interstitials and vacancies in the lattice, uniformly throughout the sample. We have observed gradual decrease of amplitude of the -process upon increasing the radiation dose, along with an increase of TG, while the other (-process) has been left unchanged. Increase of TG depends on the irradiation dose, and consequently on the domain size, in the activated manner (see Figure). It follows closely the temperature dependence of free carrier density, which does not change with the irradiation. Our results confirm previously suggested freezing criterion for CDW phase [1]. [1] D. Starešinić et. al. Phys. Rev. B 65 (2002) 165109.

charge density waves; glass; defects; glass criterion

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