Ordered structures in Fe3O4 kerosene-based ferrofluids

Journal of Applied Physics - Tập 81 Số 8 - Trang 4275-4277 - 1997
Chin‐Yih Hong1,2, Iksu Jang3, H. E. Horng3, Cheng-Ke Hsu1,2, Y. D. Yao4, H. C. Yang5,6
1Da-Yeh University
2Department of Mechanical Engineering, Da-Yeh Institute of Technology, Chang-Hwa 515, Taiwan
3Department of Physics, National Taiwan Normal University, 88, Section 4, Ting-Chou Road, Taipei 117, Taiwan
4Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan
5Department of Physics, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan
6Graduate Institute of Electro-Optical Science And Technology

Tóm tắt

The patterns of kerosene-based ferrofluid films in applied parallel and perpendicular magnetic fields were studied. The time dependence of quasiperiodic chains in a parallel magnetic field, the perfect hexagonal crystal structure in a weaker perpendicular field, and the labyrinthine pattern in a stronger perpendicular field were observed. The Fe3O4 kerosene-based ferrofluids that we used in this study were synthesized by the coprecipitation method. As the parallel external magnetic field was applied to a ferrofluid film, the ordered quasiperiodic chains were obtained. On the other hand, the initial nonequilibrium disordered quantum columns were formed in an applied perpendicular magnetic field, and an equilibrium hexagonal structure with columns occupying its vortices was formed after two hours. The distance between these columns decreases as the strength of the applied magnetic field increases, and hence, the patterns change gradually from the hexagonal structure to a labyrinthine pattern with the strength of the perpendicular field above a critical value. Thus, a phase transition exists in the ferrofluid film system as the field strength increases.

Từ khóa


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Thông tin
Thông tin xuất bản

Journal of Applied Physics

Tập 81 Số 8

4275-4277

Thông tin tác giả