Room temperature variation in dielectric and electrical properties of Mn doped SnO2 nanoparticles

Abstract

Pure and Mn doped SnO2 nanoparticles of the composition MnxSn(1-x)O2 where (x = 0.0, 0.03, 0.05, 0.07) were synthesized by sol gel auto combustion method. Structural studies performed by XRD and EDS suggest that the crystal system remains pure rutile with a tetragonal structure even after the doping of Mn. The EDS analysis reveals that both Sn and Mn elements are present in the sample which confirmed the successful doping of Mn in the SnO2 host structure. The identification of the various chemical bonds present in the pure and Mn doped samples has been carried out through Fourier Transform Infrared spectroscopy. FTIR spectrum has been recorded in solid phase using KBr pellets technique in the regions of 4000–400 cm-1. The complex dielectric constant, complex impedance, and a.c. conductivity have been studied as function of frequency and composition using LCR meter. Dielectric constant and loss was found to decrease with the increase in frequency and the obtained results have been explained on the basis of Maxwell-Wagner model. A.C. conductivity was found to increase with the increase in frequency due to hopping between charge carriers. It increases with the increase in dopant level which may be due to the free electron density and crystalline size.