I am studying some solid state physics, in particular magnetism; I have a few questions about the explanations. My understanding is that paramagnetism is primarily an effect of the electron's spin-angular momentum: an unpaired electron will have a dipole moment which preferentially aligns with an external field, so the magnetization is proportional to the applied field. On the other hand, diamagnetism is an effect of orbital angular momentum of electrons. What I don't understand is why the above argument cannot be applied to an electron with orbital angular momentum: surely an orbiting electron creates a dipole moment which aligns preferentially with an applied field? Or is it simply that the Lorentz force is much more powerful? (But if the Lorentz force were more powerful, then unpaired electrons [which have orbital angular momentum] should also exhibit diamagnetism, in contradiction of the prior explanation). Thanks for bearing with me.