STRUCTURE REDETERMINATION AND MAGNETIC ST UDIES ON MN2SNS4

The crystal structure of Mn2SnS4 was redetermined by single crystal an d powder X-ray studies. It has a deficient NaCl superstructure crystal lizing in the orthorhombic space group Cmmm proposed by Wintenberger a nd Jumas in 1980 (Z = 2, a = 740.7(1), b = 1047.5(1) and c = 366.7(2)p m, R(f) = 1.4% for 266 unique reflections with I > 0 sigma(1)). Some a dditional reflections, which are not compatible with this cell, can be refined assuming formation of twinned trilling crystals. Mn2SnS4 unde rgoes antiferromagnetic ordering below 160K. The effective magnetic mo ment mu(e)ff of Mn2+ is 5.92 B.M. The IR and Raman spectra display 5 a nd 3 bands in the range 150-320 cm(-1), respectively.