Single-crystal and powder neutron diffraction study of the FeXMn1−XS solid solutions

The α-MnS-based FeXMn1−XS (0 < x < 0.3) solid solutions are synthesized and shown to be new Mott materials with the rock salt structure. Neutron diffraction data show that the chemical-pressure-induced Neel temperature shift from 150 (x = 0) to 200 K (x = 0.29) observed in these materials is accompanied by a decrease in the NaCl-type cubic lattice parameters. It is established that at the symmetry transformation in the compositions with x = 0.25 and 0.29 the structural transition occurs, which is followed by the magnetic transition. These features make the FeXMn1−XS solid solutions interesting for both fundamental study of the interrelation between the magnetic, electrical, and structural properties in MnO-type strongly correlated electron systems and application.