Anharmonicity-induced glasslike transition in a plastic crystal without α relaxation

In the low-temperature crystal phase of TlNO2 studied by dielectric spectroscopy (10 mHz to 3 GHz), the α-relaxation process does not evolve, and the molecular dynamics is controlled only by one relaxation process with Arrhenius energy of 19.8 kJ mol-1. Its characteristic time is comparable to the measurement time scale at ∼62 K, where its Cp, the expansivity α, and the T derivative of the mean-square atomic displacement decrease in a manner …