Magnetization, M,'s defined as the quantity of magnetic moment per unit volume, V::mathbf = 0 In this sense −μ0∇·M plays the role of a "magnetic charge density" analogous to the electric charge density ρ. Magnetization's volume density of magnetic moment. That's: if a certain volume has magnetization M then the volume element dV has a magnetic moment of dm = MdV. Magnetization Dynamics » :Main article: Magnetization dynamics The time-dependent behavior of magnetizatio… (More on Magnetization)