Preparation, Characterization And Study Of Properties On Conductive Nanocomposite Powders

ATO (antimony-doped tin oxide), which is a n-type semiconductor, has excellent optic and conductive properties. It is widely used in dope, fiber, paper making, package, and architectural material et al. fields as anti-static material. It has more advantages rather than other anti-static material, such as graphite, surfactant, and metal powder. Additionally, it is used in optoelectronic display device, transparent electrolyte, solar cell, heat-able window, catalysis. Nano-composie materials are the tendency of composite materials. Among them, Core-shell structured composite materials are intensively interested due to their multi-function and ability to fine-tune properties. We have done some research about ATO composite material based on substrates such asα-Fe₂O₃, SiO₂ and NiFe₂O₄ on the properties of conductivity, optics and magnetism. The results are shown as below:Firstly, FeCl₃, as reaction materials were used to prepare monodispersed hematite nanoparticles. Then they were coated with ATO nanoparticles using precipitating method with CO(NH₂)₂ as a precipitant. The optimal preparing condition in our experiment is: .n(Sb)/n(Sn)=10%, SnO₂/α-Fe₂O₃=70w%,calcined at 700℃for 1 h.. The resistance of composite powder is 86.7Ω·cm under this condition.Secondly, after the preparation of 250nm silica microspheres with St(o|¨)bber method, we prepared core-shell structured SiO₂/ATO light colored monodispersed conductive particles using the same method above, and we also studied the optic properties of the composite particles. The experiment results show that the composite material has good transmittance in visible region and owes photoluminescence properties. It also has good conductivity of 17.5Ω·cm. An emission peak at 396nm is observed.Thirdly, NiFe₂O₄ nanoparticles were initially prepared in a sol-gel route. As prepared nanoparticles were then coated by ATO conductive layer via sol-gel method. The magnetic and electric properties of composite material were studied. The results indicated that the saturation magnetization of multi-functional material is 12.5emu/g and the resistance is decreased 2 orders compared to pure nickel ferrite to 174Ω·cm.