Research On Synthesis Of SrCO₃ And SrTiO₃ Nanopowders

Nano-sized materials are researched popularly at present. SrCO3 and SrTiO3 are attracted attention because of their superior performances. In this paper SrCO3 powders are first time synthesized successfully by low temperature solid state reaction with SrCl2 . 6H2O and (NH4)2CO3. The size of SrCO3 is about 30-50nm.Compared with liquid state method, this method produces little conglomeration and is easy to synthesize nanopowders. Symbol that reaction is over has been investigated. The process is simple and produces little pollution, so it is called "green method" and has a bright future.On the basis, precursors are obtained by two step milling with SrCl2 .6H2O, TiOSO4.H2O and (NH4)2CO3. SrTiO3 powder with a particle size of about 100nm is prepared through calcining precursors. The effect of grinding way on product is investigated. At the same time, it is confirmed through experiment that the temperature of calcination is about 900 which is lower than that of high temperature solid state reaction with SrCO3 and TiO2. So the performance of SrTiO3 ceramics can be improved definitely. In order to reduce the reaction temperature and particle size, SrTiO3 powder with a particle size of about 70nm is synthesized by sol-precipitation method with SrCl2 .6H20, Ti(C4H9O)4 and KOH. The effects of PH value, reaction temperature, agitation speed and temperature of last treatment on SrTi03 powders are investigated. The process of synthesis of SrTiO3 powders contains no high temperature calcination. The size of powders can be controlled readily through modifying the factors of process.