Effect of stirring time on size and dielectric properties of SnO2 nanoparticles prepared by co-precipitation method

Chemical co-precipitation method is employed to examine the effect of stirring time on particle size and dielectric properties of SnO2 nanoparticles. XRD patterns followed by Rietveld analysis revealed the as-prepared SnO2 samples to be pure tetragonal (P42/mnm) with rutile structure. The average crystalline size increases from 26 nm to 32 nm as the stirring time is increased from 5 min to 20 min and is confirmed from TEM measurements. The appearance of additional Raman peak at about 540, 574 and 696 cm−1 is an indicative of the characteristic of crystal symmetry due to the nano-size and agglomeration of grains in nanocrystalline tin oxide. XPS analysis reveals that in SnO2 Sn exist in 4+ oxidation state. The dielectric constant and loss tangent of 5 min stirred SnO2 sample is greatest as compared to samples prepared at increased stirring time.

► Rietveld analysis revealed SnO2 samples to be pure tetragonal (P42/mnm) with rutile structure. ► Crystalline size increases (26–32 nm) with increase in stirring time from 5 to 20 min. ► Additional Raman peaks is a characteristic of crystal symmetry due to agglomeration of nano-grains. ► XPS reveals that in SnO2, Sn exist in 4+ state. ► The dielectric constant and loss tangent decreases with increasing stirring time.