Memory effect in ferroelectric-semiconductor with incommensurate phase TlGaSe2

The paper is devoted to the investigations of the non-equilibrium properties of the incommensurate (INC) phase of the improper ferroelectric-semiconductor TlGaSe2. The influence of the prehistory of the heat treating of the crystal, i.e. annealing at a fixed, stabilized temperature in the region of INC-phase on the dielectric constant (ε) in the vicinity of the phase transition (PT)-INC phase (the commensurate (C) ferroelectric phase) was studied. The peculiar case of the memory effect leading to the temperature range change of the INC-phase existence is observed for the first time in TlGaSe2.