Investigation of thermal stability, structure, magnetic and dielectric properties of solvothermally synthesised SnFe2O4
P. Lavanya Rathi, Deepa Seetharaman
Abstract
SnFe2O4 nanoparticles have found wide applicability in recent times. An investigation of the thermal behaviour is important for its utility in dielectric/energy applications that involves heat treatment. The present work reports the synthesis of SnFe2O4 nanoparticles and the investigation of the thermal stability, magnetic and electrical properties on annealing. SnFe2O4 nanoparticles were synthesized by the solvothermal method and characterized using Thermogravimetry, X-ray diffractometry, Scanning and Transmission Electron Microscopy and Vibrating Sample Magnetometry. The spinel structured SnFe2O4 nanoparticles showed superparamagnetic behaviour with MS = 10.5 emu/g and paramagnetic transition at 517°C. On annealing in air between 300°C and 1100°C, the spinel phase was found to be stable until 500°C, but decomposed to tetragonal and hexagonal Fe–Sn oxides beyond 550°C. The resultant oxides were antiferromagnetic or weakly ferromagnetic. Electrical measurements revealed large dielectric constant (∼104) and dielectric loss <9 over a wide frequency range for SnFe2O4 and the decomposed Fe–Sn oxides.