Synthesis of nanosized (Co, Nb, Sm)-doped SnO 2 powders using co-precipitation method

Abstract

Synthesis of SnO 2 powder in order to make varistor properties is technologically important. This study aims at examining the process of making nanosized (98.95 − x)SnO 2 + 1CoO + 0.05Nb 2O 5 + xSm 2O 3 (mol%) ( x = 0.05, 0.10, 0.20, 0.50, 1.00 and 2.00) powders using co-precipitation method. Some nanopowders were studied through XRD, SEM and FTIR analyses. The XRD patterns displayed only a tetragonal rutile structure for different molar ratios of samarium oxide (Sm 2O 3). The mean crystallite size of the sample doped with 0.05 mol% Sm 2O 3, calcined at 700 °C for 2 h, was about 10 nm. The SEM micrograph of this sample revealed some nanosized spherical particles with a size range of 45–70 nm. The Sm-rich surface prevented the nanoparticles from growing during the calcination at 700 °C.