Anomaly in C p/C v: A possible signature of a liquid-glass transition

Brillouin scattering from two classic glass-forming materials, ZnCl2 and glycerol, reveals a maximum in the ratio (γ) of specific heats Cp and Cv as a function of temperature. We propose that the temperature at which the maximum in γ occurs in our materials may be indicative of a ‘‘liquid-like’’ to ‘‘solid-like’’ transformation. As such it may be a convenient thermodynamic signature of a ‘glass’ transition.