A New Method: Study on Individual Magnetic Nanoparticles by Frequency-Modulated Magnetic Force Microscopy

Author

Xiang Li ; Zhenghua Li ; Deng Pan ; Yoshimura, Satoru ; Saito, Hiroshi

Author_Institution

Sch. of Mater. Sci. & Eng., Univ. of Shanghai for Sci. & Technol., Shanghai, China

Volume

50

Issue

8

fYear

2014

fDate

Aug. 2014

Firstpage

1

Lastpage

4

Abstract

Individual magnetic Fe₃O₄ nanoparticles were imaged using the developed frequency-modulated magnetic force microscopy (FM-MFM) technique. High-resolution imaging of ac magnetic field from individual magnetic nanoparticles was demonstrated by FM-MFM with a high-coercivity FePt tip. It was found that the amplitude and phase images of ac magnetic field were obtained separately using the technique with a lock-in amplifier. The distribution of magnetic field gradient of the individual nanoparticles is clearly presented. It was observed that magnetic nanoparticles can be more precisely detected by FM-MFM. The results are significant for study of the real magnetic field distribution of individual magnetic nanoparticles (~20 nm), which provide some valuable information for the analysis of nanoscale magnetic features.

Keywords

coercive force; iron compounds; magnetic force microscopy; magnetic particles; nanomagnetics; nanoparticles; FM-MFM; Fe₃O₄; ac magnetic field; amplitude images; frequency-modulated magnetic force microscopy; high-coercivity FePt tip; high-resolution imaging; lock-in amplifier; magnetic field gradient distribution; magnetic nanoparticles; nanoscale magnetic features; phase images; Magnetic domains; Magnetic hysteresis; Magnetic resonance imaging; Magnetic separation; Magnetostatics; Nanoparticles; Soft magnetic materials; AC magnetic field; frequency-modulated magnetic force microscopy (FM-MFM); individual magnetic nanoparticles; magnetic domain structures;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2014.2305915

Filename

6739077