纳米复合Fe-SiO_2粉体的制备和结构

Preparation and Structure of Nanocomposite Fe-SiO2 Ultrafine Particles

采用非醇盐溶胶－凝胶工艺可获得Ｆｅ与Ｓｉ摩尔比达４．５／１的均匀凝胶，发现可以通过控制ＳｉＯ２的含量和热处理条件来控制相结构和晶粒尺寸，热处理过程中α－Ｆｅ相是由Ｆｅ３Ｏ４相还原而来，材料中有大量氧参与反应是工艺中采用了沉淀胶溶步骤的结果，最终制备了纳米复合Ｆｅ－ＳｉＯ２粉体。

An unalcolate sol-gel method was employed to prepare xerogel in which the molar ratio of Fe and Si was up to 4.5,and nanocomposite Fe-SiO2 ultrafine particles were prepared through further heating process.It was detected that the structure and crystallite sizes could be controlled when different SiO2 content and heating temperatures were chosen.-Fe was derived from the reduction of Fe3O4.The existence of oxygen during the heating process resulted from the peptization step.