Pressure and temperature variation of the depolarized light scattering spectra of the fragile glass-former liquid salol

The pressure and temperature dependences of the depolarized light scattering spectra of salol have been measured at isobaric condition P = 1 bar for T between 328 and 393 K, and at isothermal condition T = 343 K for P between 1 and 625 bar, i.e. outside the metastable liquid region. The experimental results for both the alpha- and beta -relaxations can be well described by the Mode Coupling Theory. The independence of the power-law parameters alpha, and consequently b and gamma, from the thermodynamic variables T and P is demonstrated. The critical temperature T-c at 1 bar and the critical pressure P-c at T = 343 K have been determined from the normal liquid state.