Structural, electronic, and magnetic properties of Co doped SnO2 nanoparticles

We present a detailed study on the structural, electronic, and magnetic properties of chemically synthesized Sn1−xCoxO2 (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 Sn1−xCoxO2 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 Sn M5,4-edge and Co L3,2-edge were performed to probe the local environment of Sn and Co ions in the SnO2 matrix. The NEXAFS at Co L3,2-edge, along with multiplet calculations, indicate that the Co is substituted at the Sn site in SnO2 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.