Ronald L. Jacobsen

Analysis of Young's modulus anomaly at the Peierls transition in TaS3

Abstract The temperature dependence of Youngs modulus in o -TaS 3 in the vicinity of the charge-density-wave phase transition is analyzed. It is assumed that strain enters the free energy through a strain-dependent transition temperature T p . Successful fitting to data requires the inclusion of a quadratic term in the strain dependence, in addition to the usual linear one. This is equivalent to introducing a term in the modulus proportional to the charge-density-wave gap. The ratio between linear and quadratic terms is consistent with a previous measurement of the stress dependence of T p .

Measure of the elastic and transport properties of TaSe3 through the stress-induced phase transition.

Abstract It is known that a stress-induced phase transition exists in TaSe3. [1, 2] We have simultaneously measured the stress, strain and resistance in TaSe3 samples through this phase transition. We have performed these measurements over a range of temperature from 25K to 300K We have also evaluated Youngs modulus, Y, over this same range and find values which are comparable with those obtained for TaS3 and NbSe3. The modulus appears to have two levels; a high stress and low stress value which is consistent with the origin of the transition being structural in nature. The dramatic electronic properties that this material exhibits under stress are discussed in terms of this structural transition.