Frequency Dependency of magnetic Susceptibility in Dried Ferro Fluid

Frequency dependency of magnetic suseceptibility with two Bartington frequencies shows considerable variation with grain size and it seems that the magnetic interaction between the grains has considerable influence on the degree of this dependency. MPMS (Magnetic Property Measurement System) located at the University of Liverpool, Physics Department, has the ability to measure susceptibility from 0 to 1000 Hz and from liquid helium to room temperature. For three different superparamagnetic (SP) grain sizes of magnetite suspended in hydrocarbons, Ferro Fluid (F.F.), the variation of magnetic susceptibility in the whole range of frequencies, at room temperature, were examined to show how the frequency dependency of magnetic susceptibility changes with known grain sizes and also determine whether the magnetic susceptibility of SP grains is influenced by an interactive regime. Our results support the effect of interaction between SP grains (nano particles) on magnetic properties of Dried Ferro Fluid (D.F.F.).