Rare Earth Magnets
Made from alloys of rare earth elements, rare earth magnets are strong permanent magnets. As they are stronger than ferrite or alnico magnets, the magnetic field produced by them are also higher.
Some of the common applications of the rare earth magnets are :
- They are used in computer hard drives.
- Rare earth magnets also find their utility in high-end speakers.
- Useful in experiment with diamagnetic levitation.
- Helpful in the study of magnetic field dynamics.
- They are also studied for a superconductor levitation.
Based on the applications and properties earth magnets are of two types:
Process of Making Rare Earth Magnets
The rare earth magnets are made by using different process involving various stages. The popular stages of the production of rare earth magnets are:
- The first stage is the manufacture of rare earth element alloys.
- The metal alloy is then finely powdered.
- The next step involved is pressing of powder either isostatically or pressing through die process.
- The particles so pressed are oriented.
- Sintering of the element is done accordingly.
- The shapes are then sliced into desired shapes and sizes.
- The coating is done thereafter.
- After finishing the above tasks, the finished shapes are magnetized.
Below is the graphical representation of making earth magnets:
About Rare Earth
Rare elements consists of group of seventeen elements having atomic numbers 21, 39, and from 57 to 71. The elements having atomic numbers between 58-71 are called as lanthanide. As these elements have strong affinity for the non metallic elements due to which they are used for producing alloys which are used in metallurgical industries. They occur in low concentration in the nature. However in certain minerals, where they occur as mixtures, they occurred in high concentration.
Rare elements find their application in glass, ceramic, lighting, and metallurgical industries. These elements have properties of exhibiting light when heated with oxides due to which they are used in cored carbon arcs. Rare earths also find their application in the petroleum industry as catalysts. Some of the rare earth elements like Yttrium aluminum garnets (YAG) are used in the jewelry trade as artificial diamonds.
As per latest research in dissimilar crystalline environment rare earth ions compete with one another and undermine the magnetic performance of the highest performance magnets. These findings also pointed the need for specialized atomic engineering of the material - manipulating the rare-earth local atomic structure to fully utilize the rare-earth contribution in next generations of magnets. This research will perhaps help the manufacturers to manipulate the rare earth ions atomic structure to improve the performance of earth magnets in future.
Table: Rare Earth