Magnetic study of two isotypic manganese chloro-sulfides: MnSbS2Cl and the new compound MnBiS2Cl

Among the MnPnQ2X compounds (Pn: pnictide; Q: chalcogen; X: halogen), two isotypic chloro-sulfides, MnSbS2Cl and MnBiS2Cl, have been studied. MnBiS2Cl is a new compound synthesized by solid state reaction at 500 °C. It is orthorhombic, space group Pnma  , with a=9.502(2)a=9.502(2), b=3.8802(8)b=3.8802(8), c=12.305(3)Å, V=453.7(2)Å3, Z=4Z=4. Its X-ray single crystal study shows (001) waved layers of MnS4Cl2 octahedra, opposite edge-sharing along bb, and corner-sharing along aa. Similar magnetic susceptibilities for both compounds have been recorded, indicating high spin Mn2+ with anti-ferromagnetic exchange. Correlatively, specific heat versus temperature shows a magnetic transition at TN=35K for the Sb-bearing compound, and a two-steps magnetic transition at 28 and 32 K for the Bi isotype. The magnetic structure of MnSbS2Cl has been determined by neutron diffraction, revealing a magnetic ordering at 1.5 K with an incommensurate wave-vector along bb (k  =[0, 0.3838, 0]). Two modulation models, sinusoidal and helicoidal, give quite equivalent reliability factors (Rmag=0.0573Rmag=0.0573 and 0.0586, respectively).

The crystal structure of a new Bi chloro-sulfide was resolved. The two isotypic compounds, MnSbS2Cl and MnBiS2Cl, were studied for their magnetic properties; magnetic susceptibility and specific heat measurements are presented. Neutron diffraction revealed the incommensurate modulation of the magnetic structure of the Sb compound.Figure optionsDownload as PowerPoint slide