S. Sveleba et al., INFLUENCE OF ELECTRIC-FIELD AND MECHANICAL STRESSES ON THE PROPERTIESOF INCOMMENSURATE PHASES IN (N(CH3)4)2ZNCL4 AND (N(CH3)4)2COCL4 CRYSTALS, Physica status solidi. a, Applied research, 140(2), 1993, pp. 573-585
The temperature dependences of birefringence increment (delta(DELTAn))
and dielectric permittivity (epsilon') of (N(CH3)4)2ZnCl4 and (N(CH3)
4)2CoCl4 are measured. The long-periodic commensurate phases appear wi
thin the incommensurate phase under the influence of external electric
fields (E) and mechanical stresses (sigma). The (E, T) and (sigma, T)
phase diagrams are obtained.