Identification of Mn dopant in the structure of TIInS2 layered semiconductor

Abstract

The structure of TlInS2 layered semiconductor doped with 0.3% concentration of Mn impurity has been investigated by using x-ray diffraction (XRD) and Electron Paramagnetic Resonance (EPR) spectroscopy. The experiments were carried out to probe the local environment surrounding the Mn dopants in the crystal structure of TlInS2. The interatomic distances between Mn - ions and neighboring atoms and effective valence of Mn - ions were determined. XRD - investigation indicated that the effective valence of Mn ions in TlInS2 is close to +4. It has been obtained that the EPR spectra of TlInS2 + 0.3% Mn consist of a broad resonance line stemming from interacting spins and a set of hyperfine structure lines originating from the paramagnetic Mn2+ ions. No EPR signal was observed in undoped TIInS2 semiconductors. The spectra revealed the incorporation of the paramagnetic Mn-cations with low symmetry site in the structure of host TlInS2 semiconductor crystal. The spin-Hamiltonian parameters of paramagnetic Mn-centers have been estimated (g = 1.9982 and hyperfine splitting constant A(z) = 88G, where z axis is perpendicular to layers). The observation of low field broad resonance lines indicates the magnetic inhomogeneity of the sample. It is assumed that weakly interacting Mn-ions in low symmetry site of host TlInS2 lead to the formation of spin cluster states, which can be considered as a precursor in preparation of new diluted magnetic semiconductor materials on the base of TlInS2.