Dielectric properties, conduction mechanism, and possibility of nanodomain state with quantum dot formation in impurity‐doped gamma‐irradiated incommensurate TlInS 2

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. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)