Preparation And Characterization Of Ito (indium Tin Oxide) Nano-powders

ITO nanopowders have been prepared by chemical coprecipitation method and hydrothermal process. The effects of coprecipitation process parameters on the prepared ITO powders were studied, such as pH, sintering temperature, dispersant and appendent methods. The small particle size, high surface areas, the well particle distribution and fine cubic structure crystallization ITO nanopowders were obtained under the condition of the sintering at 700℃ for 2h after the indium trihyoxide for ITO was washed by dispersant Na₂SiO₃ at filtration.The effects of hydrothermal process parameters on the prepared ITO crystal were investigated, such as hydrothermal temperature, hydrothermal time, mineralizer and medium. ITO crystal was not prepared by hydrothermal method under 300℃.In(OH)₃ crystal and InOOH crystal were prepared by hydrothermal process, then hexagonal structure ITO crystal was obtained through stinering them.Different structure ITO crytal were obtained by two methods. The result shows that different indium trihyoxide cause different faces of growth, which can be well explained by the morphology of crystal.The effects of Sn doped, sintering temperature and indium trihyoxide were discussed after the electronical properties, microwave and infared ray absorbing capability of ITO were tested. It has excellent microwave and infared ray absorbing capability that ITO powders was prepared by hydrothermal(220℃,6h)-sintering (450℃,2h) method and 10wt% of Sn doped level. These phenomena have been discussed based on the mechanism of crystal growth, theory of n-type semiconductor's energy band, carrier concentration and mobility in this paper.