Elastic singularities at the Peierls transition

We consider the elastic softening of quasi-one-dimensional materials near the Peierls transition caused by critical fluctuations in the charge-density-wave order parameter. Singularities in the elastic constants and thermal expansion are related to those in the specific heat. Our analysis suggests that a correction to scaling dominates the asymptotic critical behavior over the observed range of temperatures. Experimental data are used to estimate the width of the critical region according to the Ginzburg criterion.