Synthesis and magnetic characterizations of TlIn1-xFexS2 solid solution with x=0.016 as a new low - dimensional dilute magnetic - semiconductor material

Abstract

In this study, TlInS2 layered semiconducting compound in which In3+ ions were partially substituted by similar to 1.6 % Fe3+ transition metal ions was prepared by means the Bridgman - Stockbarger technique. The crystal structure of TlIn1-xFexS2 with x = 0.016 in combination with magnetization dynamics and magnetic resonance measurements have been studied. Energy dispersive X-ray (EDX) spectrum of Fe - substituted TlInS2 compound confirms the presence of all the constituent elements in stoichiometric proportions. We concluded that the magnetic properties of TlIn1-xFexS2 were induced by substituting trivalent iron atoms in the place of In3+ ion sites located at the center of (In3+S42-) structural units of TlInS2 crystal. EPR study reveals that the local site symmetry around 4 Fe3+ center is orthorhombic. The orthorhombic local symmetry can be considered to originate crystal field arising from Tl ligands in the trigonal cavities surrounding Fe3+ transition metal ion. The angular dependence resonance lines show that the crystal lattice contain two structurally equivalent Fe3+ centers localized at different tetrahedron arrays of crystal structure. The temperature dependences of the magnetization measured in the zero field cooling (ZFC) and field cooling (FC) regimes in the magnetic field of similar to 50 Oe is found to correspond to a paramagnetic behavior at low temperatures. It has been founded that Fe moments in the TlInS2 host lattice can be ordered to ferromagnetic - like structure. This conclusion in magnetic behavior of TlIn1-xFexS2 compound is well justified by the existence of very narrow hysteresis loops in the field dependent magnetization curves. Thus, in this work we propose that Fe - diluted TlInS2 is a new and promising dilute magnetic semiconductor with a large potential for future spintronic applications.