Manipulating Chladni Patterns of Ferromagnetic Materials by an External Magnetic Field

Abstract

Ernst Chladni is called the father of acoustics for his work, which includes investigating patterns formed by vibrating plates. Understanding these patterns helps research involving standing waves and other harmonic behaviors, including studies of single electron orbits in atoms. Our experiment vibrates circular plates which result in well-known patterns. Alternatively to traditional experiments that used sand or salt, we use magnetic materials, namely iron filings and nickel powder. We then manipulate the patterns by applying a localized external magnetic field to one of the rings that moves a segment of the magnetic material in that ring to the next inner ring. The results show a significant decrease in magnetic field necessary to move the magnetic material at higher frequencies as well as a significant decrease in the magnetic field required to move the magnetic material as nickel powder is substituted for iron filings while keeping the mass constant.