(dī, ∂ mag net’ ik) Having net negative magnetic susceptibility and a permeability less than that of free space (less than unity in the cgs system). The motion of an electron about a nucleus produces a miniature circular current whose magnetic-moment vector precesses around an applied external field. This additional periodic motion produces a magnetic moment opposite in direction to the applied field. Diamagnetic effects rarely exceed one nanotesla, the most evident diamagnetic anomalies caused by salt domes generally are evident only because other magnetic sources are so far away. Compare paramagnetic and ferromagnetic.