In this work, we report the room temperature ferromagnetism in Sn_1-xFe_xO₂ and S_n1-xNi_xO₂ (x = 0.00, 0.03 and 0.05) nano-crystalline powders. All the samples were prepared using co-precipitation method. X-Ray Diffraction (XRD), transmission electron microscopy (TEM), energy dispersive x-ray analysis (EDAX), UV-visible absorption spectroscopy and room temperature magnetization measurements were performed to study the crystal structure, morphology, elemental analysis, optical band gap and magnetic properties of Fe and Ni doped SnO₂. TEM results depict the formation of spherically shaped and small sized nanoparticles of the diameter of ∼ 3 nm. The band gap energy of the Fe and Ni doped samples found to decrease with increasing their concentrations. The higher saturation magnetization was observed in low concentration Fe and Ni doped tin oxide.

We present a detailed study on the structural, electronic, and magnetic properties of chemically synthesized ${\text{Sn}}_{1-x}{\text{Co}}_x{\text{O}}_2$ ($x=0.00$ to 0.05) nanoparticles. X-ray diffraction and transmission electron microscope measurements were performed to analyze the crystal structure and morphology of ${\text{Sn}}_{1-x}{\text{Co}}_x{\text{O}}_2$ nanoparticles. The energy dispersive x-ray analysis measurements were performed to check the possible presence of any impurity elements in the nanocrystals. The near edge x-ray absorption fine structure (NEXAFS) experiments at $\text{Sn}{\text{M}}_{5,4}$ -edge and $\text{Co}{\text{L}}_{3,2}$ -edge were performed to probe the local environment of Sn and Co ions in the ${\text{SnO}}_2$ matrix. The NEXAFS at $\text{Co}{\text{L}}_{3,2}$ -edge, along with multiplet calculations, indicate that the Co is substituted at the Sn site in ${\text{SnO}}_2$ matrix with $+2$ charge state and do not form metallic clusters and other oxide phases. The ferromagnetic nature of these materials was confirmed by x-ray magnetic circular dichroism and room temperature magnetization hysteresis loop measurements.