Dielectric properties, conduction mechanism, and possibility of nanodomain state with quantum dot formation in impurity‐doped gamma‐irradiated incommensurate TlInS₂

Abstract

Temperature-dependent dielectric and conduction properties of the impurity-doped and gamma-irradiated samples of TlInS 2 semiconductor-ferroelectric with incommensurate phase are presented. As found, in both cases a stable relaxor state is emerging in the material with temperature provided that the central ion in InS 4 tetrahedron is replaced by an impurity atom such as Mn or Cr, or radiation dose exceeds 400 Mrad. Same as NMR-studies, the present work drives to a conclusion that In-displacements are among the components of the order parameter of the incommensurate phase transition. The origin of the non-activated conductivity observed in the relaxor state of TlInS 2 is assumed to be resonance tunneling executed by charge carriers from electron levels in the band gap through potential barriers created by incommensurate superstructure.

Electronic properties and phase transitions in low-dimensional semiconductors

“…Summarizing, we see that despite some discrepancies in the number of observed anomalies and in their positions in the temperature scale, the majority of the investigators agree that there are four anomalies in the temperature dependence of the various physical properties of TlInS 2 near the temperatures of 79,170,[194][195][196][197] In addition, we would like to mention very interesting recent works of Sardarly et al [209][210][211][212][213][214][215][216] who doped TlInS 2 crystals with ∼0.1 at.% Cr, Mn, Yb, Sm, Bi, Fe, Ge or La. The authors have shown that even slight deviations from stoichiometry have a significant effect on the dielectric properties of the ferroelectric TlInS 2 crystals.…”

Prospective Application of A3B3C62 Type Semiconductors for Developing Nano-size Electronic Devices

“…Hanias and Anagnostopoulos [12], studying the current-voltage (I-V) characteristics of a TlGaTe2 crystal, detected the effect of negative differential resistance and voltage oscillations in the region of negative differential resistance. Our investigations [4,5,[13][14][15][16][17][18][19][20] revealed that TlGaTe2 chain crystals are subjected to phase transition in superion state, and demonstrated giant dielectric relaxation, substantial increase of dielectric permeability, and negative differential conductivity. All of these effects are connected with the transition of systems in superion state, when there is softening of Tl 1+ sublattice (Figure 1), while prolonged along tetragonal axis c of crystal Ga 3+ -Te 2-2 chains are the core of system.…”

Optical constants at and below energy gap of layered ternary Tl compounds

“…It has been reported in a very recent work that a stable relaxor state (ferroelectric glass) overlapping with I-phase is achieved in TlMeX 2 [3], making materials of this type all the more interesting both from the view-point of underlying physics and optical memory device application in visible to near IR spectral range.…”