Structural, optical, Induced ferromagnetism and anti-ferromagnetism in SnO2 nanoparticles by varying cobalt concentration

• SnO2 nanoparticles were prepared with different cobalt concentrations (0.0 % 0.5%, 1%, 3% and 4%) by the chemical co-precipitation method.
• Structure was confirmed through x-ray diffraction (XRD) analysis.
• The optical properties were studied by measuring the reflectance spectroscopy.
• The magnetic characterization was performed.

The SnO2 nanoparticles were prepared with different cobalt concentrations (0.0%, 0.5%, 1%, 3% and 4%) by chemical co-precipitation method. The NH4OH was used as precipitating agent; the pH value, reaction time and reaction temperature were optimized during synthesis. The x-ray diffraction (XRD) pattern reveals the formation of single phase tetragonal structure of undoped and cobalt doped SnO2 nanoparticles which lies in the range of 19–22 nm calculated by De-Bye Scherrer's formula. The optical properties were studied by measuring the reflectance spectroscopy which shows that band gap energy decreases with increase in cobalt concentration. The magnetic characterization was performed by Quantum Design Physical property measurement system (PPMS). Interestingly magnetic measurements show that ferromagnetism in a Co doped SnO2 becomes visible for x=0.5% and diminishes with further increasing of cobalt concentration.