Preparation And Study Of Bifunctional Magneto-optical Composite Materials

In recent years, bifunctional magneto-optical composite materials have been widelyapplied in medical diagnosis and therapy. In the thesis, first Fe3O4nanopaticles were preparedvia ultrasonic chemical co-precipitation, and the precipitant reagents、the forms of agitationand the dispersant agents played an important part in detemining the morphologies andcrystallite size of Fe3O4nanopaticles; Secondly, Fe3O4@SiO2composite particles wereprepared via ultrasonic chemical precipitation, and the effects of the hydrolytic agents on grainsize were deeply investiged; At last, luminescent materials were coated onto the surface ofFe3O4@SiO2composite particles via precipitation method and hydrothermal method, and theeffects of the synthetic methods on luminescent intensity were studied.In the thesis, all detection instruments were as follows: X-ray diffraction, Field emssionscanning electron microscopy， Energy dispersive spectrometer, Fourier infraredspectroscopy, N2adsorption-desorption analysis, fluorescence spectrophotometer. Theresults of the analysis indicated that Fe3O4nanopaticles with high crystallinity were obtainedand special surface energy caused aggregation of Fe3O4nanopaticles. Silica was coated ontoFe3O4nanopaticles, grain size was about20nm. Fe3O4@SiO2composite particles coatedwith LaF3: Eu3+or YVO4:Eu3+were20-30nm, and Ce3+could improve luminescent intensityof composite paticles. In comparison, Bifunctional magneto-optical composite particlesprepared by hydrothermal method had better luminescent property.Finally, though comparative analysis of different results, the optimal process conditionswere obtained. The reaction conditions of Fe3O4nanopaticles were as follows: the precipitantgent:ammonia、the forms of agitation: ultrasonic wave and mechanical agitation、thedispersant agent: PEG6000. The hydrolytic agent of Fe3O4@SiO2composite particles wasNH4Cl. Bifunctional magneto-optical composite particles were prepared via hydrothermalmethod.