The synthesis, structure, and electronic properties of a series of new quaternary layered sulfides, NaCuMS2 (M = Mn, Fe, Co, Zn) are reported. The synthesis was accomplished by sulfurization of a mixture of oxide or sulfide and carbonate precursors of the corresponding metals by nitrogen gas charged with CS2. All of the phases crystallize in the trigonal CaAl2Si2-type structure in space group P3m1. The electrical resistivity measurements show that all of the new phases are semiconducting, with room-temperature resistivities ρRT varying from 6.2 × 10-1 to 5 × 10-2 Ω·cm, depending upon the transition metal M. The magnetic susceptibility measurements indicate the presence of localized Mn2+ ions in NaCuMnS2. The NaCuMS2 (M = Fe, Co) phases display temperature-independent paramagnetism, whereas the NaCuZnS2 phase is diamagnetic as expected. In addition, detailed low-temperature magnetic studies of the NaCuFeS2 phase revealed spin-glass-type behavior with the freezing temperature Tf ∼ 50 K.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Materials Chemistry