XRD analysis, Raman, AC conductivity and dielectric properties of Co and Mn co-doped SnO2 nanoparticles

Abstract

The dielectric behavior, AC conductivity, and optical properties of Mn- and Co co-doping SnO2 nanoparticles were investigated in this paper. Co-doped Sn0.98−xMnxCo0.02O2 (x = 0.01, 0.02, and 0.03) and undoped SnO2 nanoparticles were synthesized by sol–gel method. Pure crystallographic phases of undoped and co-doped samples were confirmed by Rietveld analyses of X-ray diffraction (XRD) patterns. From XRD patterns, it was also confirmed that no impurity phase is present in co-doped and undoped samples. The crystallite size of each sample was calculated by two ways, namely, Scherrer’s formula and Williamson–Hall (W–H) method. The crystallographic strain of the co-doped samples was estimated from W–H method and the values were compared with that of the undoped one. Raman spectra recorded at room temperature indicates that oxygen vacancy in co-doped samples was enhanced compared to that of SnO2. In addition, dielectric properties of the co-doped samples were improved compared to that of SnO2 and the AC conductivity of all the co-doped samples was lowered due to replacement of Sn ion by Mn and Co ions which indicate that the resistivity of co-doped sample increases compared to that of the pristine sample. However, the AC conductivity of undoped and all co-doped samples was increased with the increase of frequency due to charge-hopping mechanism.