Spontaneous orientational ordering in magnetic fluids

The problem of spontaneous orientational order in dipolar hard sphere fluid is studied on the basis of the BBGKY equation self-consistent solution. This self-consistent approach is used in the density functional method and proves to be equivalent to the mean field theory. In the framework of dipole-dipole interaction second order perturbation model the following effect is discovered: the self-consistent density functional approach leads to the spontaneous “ferrimagnetic'' state of the magnetic fluid induced by the dipole-dipole interaction.