Rare earth permanent magnetic material application in military field

Rare earth elements have excellent magnetic properties, it comes from the unique electronic structure of the rare earth.The 4f electronic shell has more unpaired electrons, such as trivalent gadolinium ion unpaired electrons reached 7, canproduce large magnetic moment. In addition because lanthanide 4f electronic shell with 5s, 5p, metallic state also has 6s shell, this makes 4f electronic shell is less influenced by external crystal field. This nature is not only reflected in its narrow spectral lines, good monochromaticity, and can reflect on their magnetic properties. 4f electronic shell orbital magnetic moment will not be "frozen", atomic magnetic moment to show the orbital magnetic moment and the sum of the spin magnetic moment, its value is bigger. Rare earth elements has more excellent magnetic properties. It can be used for the preparation of magnetic materials with various kinds of performance. Mainly including rare earth permanent magnet material, magnetic refrigeration materials, magnetostrictive materials.
Development of rare earth permanent magnet materials has experienced three generations:
The first generation of SmCo5 permanent magnetic material, the second generation of Sm2Co17 permanent magnetic material, the third generation of ndfeb permanent magnet material (Nb-Fe-B). So to speak, rare earth permanent magnet application in military field are everywhere. In regular communication, one end convert the voice signal into electrical signal, the other end convert electrical signal into sound signal, both need the aid of electromagnet, the motor converts electrical energy into kinetic energy, generator transforms mechanical energy into electricity needs assistance of the magnet. In the guidance of cruise missile, the effect of permanent magnet is very important. Such as the Gulf War showing great power missile "the patriot" used 4kg of ndfeb permanent magnet materials. Domestic long sword, red bird, eagle series missile is also dependent on the high performance of rare earth permanent magnet materials.