Understanding the Structural Phase transition in Mn2Sn1−xSixS4: From Defect Rock Salt to Olivine Structure

Abstract

Chalcogenides have attracted considerable attention not only due to prospective applications in in thermoelectric, nonlinear optics, solar cells, superconductivity, magnetocaloric but also because of the diverse structural and physical properties. The present article explores the impact of silicon substitution on the structural and magnetic properties of Mn2SnS4. The ternary and quaternary metal chalcogenides, Mn2Sn1−xSixS4, were synthesized through sealed tube reaction at 750 °C for x = 0 - 0.5; and at 1000 °C for x = 0.6 - 1.0. The structural phase transition from defect ordered rock salt (Cmmm) to olivine structure (Pnma) is observed with increase in silicon content in Mn2Sn1−xSixS4. Analysis of the magnetic susceptibility shows that a small amount of silicon doping in Mn2SnS4 lowers the weak ferromagnetic transition from 53 K to 30 K, while the antiferromagnetic transition at 152 K remains constant. At higher silicon content x = 0.9 (pure Pnma), peaks at the 30 K and 152 K disappears, while the peak at 85 K becomes prominent. Future studies exploring the detailed magnetic interactions in these materials may offer deeper insights for the potential applications in magnetic devices.