Synthesis, structural and magnetic properties of Ni2+ and In3+ doped cobalt ferrite and application as catalyst for synthesis of Bis-(Indolyl) methane derivatives

The Ni2+ and In3+ substituted cobalt ferrites were prepared having the chemical composition NixCo1-xInyFe2-yO4 (x = 0.0, 0.25, 0.5, 0.75, 1.0 and y = 0.0, 0.03, 0.06, 0.08, 0.1) by sol-gel auto-combustion method. The precursors were calcinated at temperature 500 degrees C. The EDAX pattern confirmed stoichiometric composition of elements of synthesized ferrite nano particles. The XRD pattern confirms single phase cubic spinel structure. Lattice constants increase as increase in In+3 ions content. X-ray density increases whereas bulk density decreases. Infrared spectroscopy of synthesized samples shows absorption bands 'nu(2)' around 400 cm(-1) and 'nu(1)' at 600 cm(-1) are allocated to the intrinsic stretching vibrations of octahedral and tetrahedral complexes respectively. Scanning electron microscopy was applied to study the surface characteristics and uniform distribution of particle size and also prepared samples are porous in nature. Transmission electron microscopy carried out to know the particle size of synthesized ferrite samples and selected area electron diffraction pattern clearly shows that particles were well crystalline in nature. Magnetic measurements of ferrite nanoparticles were done by vibrating sample magnetometer (VSM). Bis-(indolyl) methane derivatives efficiently prepared from Indole and aromatic aldehydes using NixCo1-xInyFe2-yO4 nano particles as catalyst. (C) 2021 Elsevier Ltd. All rights reserved.