New evidence for a liquid–liquid transition in a one-component liquid

Based on specific heat, x-ray diffraction and nonlinear dielectric effect (NDE) measurements the evidence for a liquid-liquid (L-L) transition in trans-1,2-dichloroethylene at TL-L approximate to T-m + 23.6 K approximate to 247 K is shown. The strong pre-transitional anomaly of NDE, similar to the one observed in the isotropic phase of nematic liquid crystals, makes it possible to estimate the weakly discontinuous character of the transition. Based on NDE measurements, the pressure evolution of the L-L transition up to almost 500 MPa was also obtained. Parameterization by the modified Simon-Glatzel-type equation made possible an insight into the negative pressure domain.