Falling velocity magnetometry of ferromagnetic microparticles

Abstract

A simple magnetometry of single ferromagnetic microparticles, which measures the falling velocity of a particle under the influence of magnetic Faraday force in air or liquid and characterizes the magnetic susceptibility of the particle, was constructed. Magnetic field gradient was applied to the falling particles and the velocity change of the falling particles was analysed taking into account the working forces to the particle. The feasibility of the present method was demonstrated by evaluating the magnetic susceptibility of ferromagnetic particles of cobalt, nickel and magnetic toner particles.