Investigation of Structural and Magnetic Properties in Inverse Spinel Compounds Fe2−xCuxSnS4

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 properties. Iron and copper-based ternary metal chalcogenides offer an extra dimension in terms of magnetism and magnetocaloric application, that makes them more intriguing. Due to their varied structural makeup and intricate magnetic properties, ternary chalcogenides based on transition metals, with the formula M2AQ4 (Q=S, Se, and Te, A=Si, Ge, Sn and M being Transition metal), have attracted renewed research interest in recent years. From earlier study in our group, it was observed that the magnetic properties in Mn2SnS4 can be tuned by suitable substitution at different sites. Mn2SnS4 shows complex magnetic properties with two magnetic transition, one at (i) an antiferromagnetic ordering below 152 K, (ii) a weak ferromagnetic ordering, possibly due to spin canting and frustration below 53 K.1 For example, with Sb substitution at Mn site the low temperature AFM transition temperature increases while substitution of Fe at Mn-site resulted in selective increase in the second transition temperature. To further understand the magnetic properties and the effect of substitution in the Fe-analogue, Fe2SnS4, we have studied the effect of Cu substitution on the structure and magnetic properties in Fe2-xCuxSnS4. In this work we repot a detailed electronic, magnetic, structural, and thermodynamic investigation on Fe2-xCuxSnS4 using both experimental and theoretical Study. From magnetic measurements, we have observed one distinct magnetic transition at 230 K, associated with ferrimagnetic ordering which can be rationalized by taking into account the changes in the distribution of magnetic centres within the structure arising from the Cu substitution at Fe site