Specific Heat of Tetrathiofulvalinium-Tetracyanoquinodimethane (TTF-TCNQ) in the Vicinity of the Metal-Insulator Transition

Abstract
Measurements of the specific heat of tetrathiofulvalinium-tetracyanoquinodimethane have been made from 45 to 70 K using ac calorimetric methods. A steplike anomaly in the specific heat is observed with transition temperature 54.8 K. The results compare favorably with predictions from a mean-field model when the crystal undergoes a Peierls distortion.