1971 Volume 44 Issue 10 Pages 2681-2684
A linear retationship was found between the transition temperature of plastic crystals and potential energy barrier hindering molecular rotation determined below or above the transition point, with the slope of the line 7.5 R and 4.1 R, respectively, where R is the gas constant. Consideration of the distribution of molecules between the librational and the rotational states showed that the transition starts to occur cooperatively when the fraction of the rotating molecules reaches a value of 1/60 and concludes with a value of 1/3. The model gives the entropies of transition which reasonably agree with the observed values.
This article cannot obtain the latest cited-by information.