Change of High-Frequency Permittivity at an Orientational Order–Disorder Transformation: A Method of Detecting Very Slow Transformations

It seems likely that order-disorder transformations in crystals of polar molecules can be detected by measuring the infrared polarization by means of the high-frequency permittivity. This is particularly valuable if the transition is slow because capacitance bridges can be bought that are sensitive to 1 ppm or less. A transition that requires several months for completion can therefore be readily detected even if the permittivity changes only slightly. (Author)