EPR study of Fe3+ centers in ternary layered TlInS2 single crystal

An iron doped TlInS2 single crystal has been studied at room temperature by Electron Paramagnetic Resonance (EPR) technique. The fine structure of EPR spectra of the paramagnetic Fe3+ ions was observed. The spectra were interpreted to correspond to the transitions among the spin multiplets (S=5/2, L=0) of the Fe3+ ion, which is split in the local ligand crystal field (CF) of orthorhombic symmetry. Four equivalent Fe3+ centers have been observed in the EPR spectra and the local symmetry of crystal field at the Fe3+ site and the CF parameters were determined. It was established that the symmetry axis of the axial component in the CF is making an angle of about 48 degree with the (ab) plane of TIM, crystal. Experimental results indicate that Fe ions substitute for In ions at the center of the InS, tetrahedrons, and the rhombic distortion of the CF is caused by Tl ions located in the trigonal cavities between the tetrahedral complexes.