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

Temperature‐dependent dielectric and conduction properties of the impurity‐doped and gamma‐irradiated samples of TlInS2 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 InS4 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 TlInS2 is assumed to be resonance tunneling executed by charge carriers from electron levels in the band gap through potential barriers created by incommensurate superstructure. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)