Dielectric properties and metastable states in ferroelectric TlInS₂ crystals

Abstract

A phase of antiferroelectric type of hysteresis preceding the transition to the ferroelectric state has been observed in Thallium Indium sulfide crystals. A possible coexistence of polar regions and domains of the ferroelectric and the T _C1 - T _C2 phases over a wide range of temperature is suggested from analysis of dielectric studies. A metastable behaviour of permittivity observed at thermocycling is explained by existence of a chaotic state below the ferroelectric phase transition temperature T _C2 = 201 K. A model of two polar sublattices in the region of phase coexistence in TlInS₂ is offered.

Key Words:

• hysteresis loop
• Thallium Indium sulfide
• chaotic state
• metastable state
• incommensurate phase
• phase coexistence