The demagnetizing factors in multidomain grains

摘要: Experiments and theory are combined in an attempt to determine how well a demagnetizing factor, N, characterizes the internal magnetic field of multidomain (MD) grain. It is shown that all previous experimental estimates N suspect only under unusual circumstances can one have much confidence determining value for field. One those when sample nearly stoichiometric, as case large synthetic magnetite crystal found here MD essentially identical its single-domain value. However, calculations show small grains depends on domain magnetization state sample. factor cannot be uniquely determined grains, but it often approximated by grains. A 10 μm roughly linear dimension separates “large” from “small” equidimensional magnetite.