METASTABILITY AND FIELD-INDUCED MESOMORPHISM

The effect of quadrupolar symmetry orienting fields on the mesophase with inner degrees of freedom showing metastability properties in the orientationally ordered state is investigated. It is established that the external field is a factor stabilizing an isostructural "conformationally ordered nematic-conformationally disordered one" transformation and, hence, inducing an intermediate conformationally disordered phase. Phase diagrams are constructed in "field-temperature" coordinates in which - unlike the standard situation - the possibility of the existence of two critical end points terminating lines of isostructural phase transitions is outlined.