Influence of dopant on structural, optical and dielectric properties of Sn1-XCoxO2 nanoparticles

In this work, the optical and dielectric properties of Co doped SnO2 nanoparticles were studied using a.c. impedance spectroscopy. X-ray diffraction (XRD) confirmed that the Co doped SnO2 powder samples have the same tetragonal structure as pure SnO2 nanoparticles. The structural, surface morphological studies, compositional analyses and optical energy band gap were investigated by XRD, Scanning electron microscopy (SEM), Energy Dispersive X-ray Analysis (EDAX), and UV-Vis Spectroscopy. It is evident from the XRD result that annealed SnO2 samples exhibits tetragonal crystal structure with crystallite size ranging from 8 to 12 nm. The optical band gaps value of doped SnO2 nanoparticles were calculated to be in the range 5.33-5.8 eV. Impedance spectroscopy was carried out at room temperature in the frequency range of 100 kHz-14 MHz to explore the electrical properties of Sn1-xCoxO2 nanoparticles. For all the Co doped SnO2 samples prepared with Co content x <= 0.04, the SnO2 lattice contracts with the increasing dopant concentration. The dielectric constant, dielectric loss and a.c. electrical conductivity decrease with the increase in Co doping concentration. The decrease of dielectric constant and dielectric loss of the nanomaterial with respect to increasing frequency suggests that this nanomaterial can be employed in the fabrication of devices used at high-frequencies.