Nucleation processes in the charge density wave state of 2H-TaSe2

The authors examine the free energy barrier associated with critical nuclei in the homogeneous nucleation of discommensurations at the commensurate-incommensurate transition in the charge density wave state of 2H-TaSe2. The various terms entering the free energy of critical nuclei are estimated within a Landau theory. The parameters in the Landau theory are deduced, as well as possible, from experiment. The energy barrier that results is reasonable, also somewhat too high to account for the homogeneous nucleation rate observed by electron microscopy. The reduction of the energy barrier due to internal strains associated with the orthorhombic domain structure is estimated.

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