Effect of mechanical stresses on anomalies of dielectric properties of the incommensurate phase in Rb2CoCl4 crystals

The influence of uniaxial mechanical stresses on the dielectric constant ϵy and polarization Py induced by an electric field is studied in the vicinity of the incommensurate-commensurate phase transition in Rb2CoCl4 crystals. It is shown that a change of the stresses results in different ϵy and Py variations depending on whether the crystal is cooled or heated and whether it is acted by stresses previously i.e. the crystal exhibits pronounced after-effects specific for incommensurate phases and caused by pinning the structural modulation on defects.