Electron paramagnetic resonance investigation of Fe 3+ doped TlInS 2 single crystal

Abstract

TlInS 2 single crystal doped by paramagnetic Fe ions has been studied at room temperature by electron paramagnetic resonance (EPR) technique. The fine structure of EPR spectra of the paramagnetic Fe 3+ ions is observed. The spectra were interpreted to correspond to the transitions among the spin multiplets ( S=5/2, L=0) of the Fe 3+ ion, which are split in the local ligand crystal field (CF) of orthorhombic symmetry. Four equivalent Fe 3+ centers have been observed in the EPR spectra and the local symmetry of CF at the Fe 3+ 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° with the plane of layers of TlInS 2 crystal. Experimental results indicate that Fe ions substitute for In ions at the center of the InS 4 tetrahedrons, and the rhombic distortion of the CF is caused by Tl ions located in the trigonal cavities between the tetrahedral complexes.