Abstract
This paper describes the aging process of the interfacial instability of magnetic fluids subjected to
vertically oriented magnetic field. The interfacial instabilities of two kinds of magnetic fluids were
observed for a long time. The time series of the interfacial instability aging (spike pattern transition) of
magnetic fluids was examined by the photographic recording methods. It was found that the interfacial
spike pattern of magnetic fluids changes with time dramatically.
