Effect of Ultrasonic Treatment on the Magnetization Enhancement of Fe3O4 Nanocrystallines
The effect of ultrasonic treatment on the morphology changes and magnetization enhancement of Fe3O4 nanocrystallines (NCs) is reported. The samples were characterized by various techniques such as X-ray diffraction, scanning transmission electron microscopy, etc. The crystallinity and the morphology of Fe3O4 NCs are obviously changed when the as-grown Fe3O4 NCs are irradiated by ultrasonic for 30 min. The magnetization of these Fe3O4 NCs after ultrasonic radiation is found to be 20 % enhanced compared to the sample without this treatment. A well dispersive magnetic fluid with the chemisorbed –OH as the surfactant is composed after ultrasonic irradiation. The mechanism of the morphology changes, magnetization enhancement and dispersibility of Fe3O4 NCs are also discussed in detail.
KeywordsIron oxide nanocrystalline Ultrasonic radiation Magnetic property Magnetic fluid
Scanning transmission electron microscopy;
High resolution transmission electron microscopy
This work is supported by the Fundamental Research Funds for the Central Universities, Foundation for Climax Talents Plan in Six-Big Fields of Jiangsu Province of China (Grant No. 1107020070) and Large Equipment Grants of Southeast University, China.