| In this paper, Fe/C, Fe/C and Fe203-Si02 nanoparticles were prepared by laser-induced vapor-phase method or sol-gel method. They were studied in system and characterized detailed.In laser-induced vapor-phase experiment, ideal products can be available by controlling experimental conditions. The main parameters include efficiency of laser, ratio of gaseous reactants, pressure of system and velocity of gas etc. , which were studied detailed in this thesis. It can be concluded from the experimental results that dispersed Fe/C(10-20nm) and Fe/C(4-10nm) nanoparticles can be prepared successfully by laser-induced vapor-phase method.Then, products of y -Fe203 were heated under increasing temperature. When products were heated above 295℃,particles changed from v -Fe203 to a -Fe203 gradually with the increase of size.It was judged from TG-DTA that all products changed into a-Fe203 at 528℃, and they were still nanosize.Dispersed Fe203 and Fe203-Si02 nanoparticles were synthesizedby sol-gel method consummately. The average diameter of the Fe203 nanoparticles were 200nm, and Fe203-Si02 products were controlled under lOOnm.Products were used as raw material of sensor. Sensitivity of the component was better than normal sensor. Experimental results indicated that blending rare metal and metal oxides with the products can improve sensitivity greatly.
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