Hysteresis and Multiple Stable Configurations in a Magnetic Fluid System
Journal of Physics: Condensed Matter
A magnetic liquid in a horizontal Hele–Shaw cell is subjected to a vertical magnetic field. The width of the magnetic fluid finger is measured as a function of applied field and compared to a theoretical model. The theoretical model uses an energy minimization procedure and predicts a double energy minimum, hysteresis, and discontinuous transitions between a circle and a finger. The experimental data set agrees very well with the theory for a well-defined magnetic fluid finger. Near the transitions, the experiments show hysteresis and support for a double energy minimum; however, the agreement is not quite so good. The discrepancy between theory and experiment near the transition region is likely due to the simplified finger model used in the theory.
Jackson, D.P. "Hysteresis and Multiple Stable Configurations in a Magnetic Fluid System." Journal of Physics: Condensed Matter 20, no. 20 (2008): e204140 https://iopscience.iop.org/article/10.1088/0953-8984/20/20/204140