Frequency dependency of magnetic susceptibility in SP magnetite grains



Using a Magnetic Property Measurement System (MPMS), we measure magnetic susceptibility continuously at frequencies from 0 to 1000 Hz for three different superparamagnetic (SP) grain sizes of magnetite (5nm, 7 nm and 10 nm) suspended in hydrocarbons (Ferrofluids). Our results confirm non-zero values of frequency-dependent susceptibility in the fine tail of nano-sized grains and provide new empirical data for the degree of interaction between SP grains (nano particles) affecting magnetic susceptibility and frequency-dependent susceptibility.