可控粒径纳米Fe_3O_4的制备及其磁性研究

本文用空气氧化法,在可见光作用下,添加配合剂(EDTA、柠檬酸、酒石酸、谷氨酸)在室温进行了不同粒径纳米Fe3O4的制备及其磁性能研究。结果表明:在可见光作用下,随EDTA、柠檬酸、酒石酸、谷氨酸等配合剂的添加,得到纳米Fe3O4的粒径有所减小、分散性有所提高;配合剂及可见光共存时,体系反应速率得到提高,高的反应速率使纳米Fe3O4晶粒减小;控制适当的光照度和添加剂的量,室温可得到11.8~29.6nm的Fe3O4颗粒。不同粒径纳米Fe3O4分别呈现出超顺磁性、铁磁性特征。

Synthesis of Variable-Sized Fe3O4 Nanocrystals and Their Magnetic Properties

This paper described the preparation of variable-sized Fe₃O₄ nanocrystals by air oxidation method under visible light irradiation at room temperature in the presence of trace EDTA, citric acid, tartaric acid, glutamic acid and discussed their magnetic properties. The results showed that adding the complexing agents (EDTA, citric acid, tartaric acid, glutamic acid) could reduce the particle size of Fe₃O₄ and increase the dispersibility of Fe₃O₄ particles under irradiation by visible light. The oxidation rate could be significantly accelerated by visible light in the presence of complexing agents. The rapid oxidation rate was favorable for the decrease of the size of Fe₃O₄ nanocrystals. The size of the Fe₃O₄ nanocrystals about 11.8~29.6 nm was obtained by controlling the intensity of light and concentration of complexing agents at room temperature. The variable-sized Fe₃O₄ nanocrystals exhibited different magnetic properties.