Control method for the tunable ordered structures in magnetic fluid microstrips

Structural evolution along the edges of magnetic fluid microstrips under external magnetic fields is investigated in this article. It was found that when the external magnetic field increased the structure evolves from an originally monodispersed state to a disordered column state, and then to several levels of ordered structures. For the ordered structure state, a one-dimensional periodic structure resulted under lower field strengths, and with an increase in field strength, more columns formed. Hence, a two-dimensional ordered array of columns was achieved. Further experimental results showed that the ordered structure can be manipulated by adjusting control parameters, such as field strength, sweep rate, fluid concentration, strip width, and strip thickness. These results lay the groundwork for utilizing controllable ordered structures in magnetic fluid microstrips to develop potential applications, such as photonic crystals or waveguides. (C) 2003 American Institute of Physics.