Influence of a Magnetic Field on the Formation of Magnetite Particles via Two Precipitation Methods
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- 作者：Fernando Vereda ; Juan de Vicente ; Roque Hidalgo-Á ; lvarez
- 刊名：Langmuir
- 出版年：2007
- 出版时间：March 27, 2007
- 年：2007
- 卷：23
- 期：7
- 页码：3581 - 3589
- 全文大小：761K
- 年卷期：v.23,no.7(March 27, 2007)
- ISSN：1520-5827
文摘
An experimental investigation is described on the effects of the presence of a magnetic field during the fabricationof magnetite particles. We considered two well-known synthesis methods: that of Massart [IEEE Trans. Magn. 1981,17, 1247-1248] for the synthesis of nanometer-sized, monodomain particles; and that of Sugimoto and Matijevi
[J.Colloid Interface Sci. 1980, 74, 227-243.] for the fabrication of micrometer-sized multidomain spherical particles.The latter method was studied with two systems of different ionic compositions that lead to two different mechanismsof growth: either growth by aggregation and recrystallization of primary particles or direct crystal growth. Whengrowth was dominated by aggregation of primary units, the magnetic field had a dramatic effect on the morphology,inducing the formation of rodlike particles. Growth dynamics of that system were studied for particles obtained inthe presence as well as in the absence of the magnetic field. Particles were also characterized by powder magnetometry,electrophoresis, X-ray diffraction, and optical absorbance techniques. Interestingly, growth dynamics of the rods crosssection were comparable to those of the diameter of the spheres. With the exception of the morphology, no othersignificant difference was found between the rodlike particles and the spheres.
[J.Colloid Interface Sci. 1980, 74, 227-243.] for the fabrication of micrometer-sized multidomain spherical particles.The latter method was studied with two systems of different ionic compositions that lead to two different mechanismsof growth: either growth by aggregation and recrystallization of primary particles or direct crystal growth. Whengrowth was dominated by aggregation of primary units, the magnetic field had a dramatic effect on the morphology,inducing the formation of rodlike particles. Growth dynamics of that system were studied for particles obtained inthe presence as well as in the absence of the magnetic field. Particles were also characterized by powder magnetometry,electrophoresis, X-ray diffraction, and optical absorbance techniques. Interestingly, growth dynamics of the rods crosssection were comparable to those of the diameter of the spheres. With the exception of the morphology, no othersignificant difference was found between the rodlike particles and the spheres.