Characterizations of transition metals doped SnO2 nanoparticle prepared by autocombustion technique

The Sni_xTMx02_8 nanoparticles samples (TM = Cr and Co with x0.015 and Fe with x0.300) were prepared by the autocombustion technique. The XRD patterns of all samples exhibit a single tetragonal rutile phase without any trace of an impurity phase. The particle size is in the range of 5- 20 nm. The diffuse reflectance spectra show the d-d band transition of the substituted transition metal ions. The band gap energies are in the range of 3.2- 3.8 eV. The Sni_xTMx02_5 nanoparticles samples with x 0.015 exhibit the weak ferromagnetic-like behavior at room temperature, while the high level dope Fe (0.100x 0.300) the samples show a superparamagnetic characteristic.