The neodymium atom can have a large magnetic dipole moment because it has 4 unpaired electrons in its electron structure as opposed to (on average) 3 in iron. In a magnet it is the unpaired electrons, aligned so that their spin is in the same direction, which generate the magnetic field. This gives the Nd2Fe14B compound a high saturation magnetization ("J"s ≈ 1.6T or 16kG) and a remnant magnetization of typically 1.3 teslas. Therefore, as the maximum energy density is proportional to "J"s2, this magnetic phase has the potential for storing large amounts of magnetic energy ("BH"max ≈ 512kJ/m3 or 64MG·Oe). This magnetic energy value is about 18 times greater than "ordinary" ferrite magnets by volume and 12 times by mass. This magnetic energy property is higher in NdFeB alloys than in samarium cobalt (SmCo) magnets, which were the first type of rare-earth magnet to be commercialized. In practice, the magnetic properties of neodymium magnets depend on the alloy composition, microstructure, and manufacturing technique employed.