Band gap tuning & Room temperature ferromagnetism of hydrothermally prepared Cobalt doped CaSnO3 nanopowders

This paper deals with the systematic investigation of microstructure, optical and magnetic properties of Co doped CaSnO3 nanostructures prepared by hydrothermal route. Detailed structural analysis using XRD, FTIR and Raman analysis reveals the formation of orthorhombic CaSnO3 with pnma space group. Optical absorption studies authenticates the tuning of optical band gap upto 1eV was achieved by varying Co concentration in Ca-Sn-O lattice. Presence of oxygen vacancies and defects in the grown nanostructures were supported by PL and EPR studies. Room temperature M-H loops implies clear occurrence of room temperature ferromagnetism in all the Co doped nanostructures and the saturated magnetization (Ms) increases with increase Co doping. The magnetization behaviour was explained based on F-centre exchange interactions mediated by oxygen vacancies. The overall findings open up a pathway to tune the ferromagnetism as well as bandgap of stannate systems by varying the concentration of transition metal dopant’s. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.