Laboratório Nacional de Luz Síncrotron (LNLS), CP 6192, CEP 13083-970, Campinas-SP, Brazil.
J Colloid Interface Sci. 2009 Nov 15;339(2):344-50. doi: 10.1016/j.jcis.2009.07.068. Epub 2009 Aug 4.
The relationship between crystallization and growth of colloidal iron oxide nanoparticles during isothermal annealing was addressed in this work. The structural, morphological and chemical modifications of the nanoparticles during thermal treatments were followed by combination of electron microscopy, X-ray diffraction and spectroscopic methods. The initially monodisperse spherical nanoparticles with amorphous and partially oxidized structure evolved during the treatments, depending on the temperature and treatment time. Core-void-shell nanoparticles or single crystal nanoparticles and hollow polycrystalline nanoparticles, both with well defined Fe(3)O(4) oxide phase, are formed depending on the conditions. This evolution was interpreted as a result of the Kirkendall effect associated to mass redistribution and fragmentation of the nanoparticles, bringing new information about the effect of post-synthesis treatments on the crystallinity and morphology of colloidal nanoparticles.
本文研究了胶体氧化铁纳米粒子在等温退火过程中的结晶和生长之间的关系。通过电子显微镜、X 射线衍射和光谱方法的结合，研究了纳米粒子在热处理过程中的结构、形态和化学变化。最初具有无定形和部分氧化结构的单分散球形纳米粒子在处理过程中会根据温度和处理时间而发生变化。根据条件的不同，会形成核-空壳纳米粒子或单晶纳米粒子以及具有明确 Fe(3)O(4)氧化物相的多晶空心纳米粒子。这种演变被解释为与质量重新分布和纳米粒子碎裂相关的 Kirkendall 效应的结果，为了解后合成处理对胶体纳米粒子的结晶度和形态的影响提供了新的信息。
