Rare earth elements refer to 15 lanthanide oxides with atomic numbers 57-71 in the periodic table, as well as 17 elements of Sc and Y with similar chemical properties of lanthanides. These 17 elements are divided into LREE and HREE .
Due to the atomic structure of the 4f electron layer, rare earth elements are extremely rich in electronic energy levels, have special properties such as light, electricity, magnetism, and nucleus, and can form a wide variety of new materials with specific properties and other materials.
Rare earth functional materials can be divided into rare earth permanent magnet materials, rare earth luminescent materials, rare earth hydrogen storage materials, rare earth catalytic materials, rare earth polishing materials and so on.
Rare earth permanent magnetic material is a kind of magnetic material made by alloying Sm, Nd mixed rare earth metals and transition metals (such as Co, Fe), pressed and sintered by powder metallurgy method, and magnetized by a magnetic field.
In 1967, StrNa discovered the first generation of rare earth permanent magnet SmCo5
In 1977, Ojima discovered the first generation of rare earth permanent magnet Sm2Co17
In 1983, Sagawa discovered the third-generation rare earth permanent magnet Nd2Fe14B
2. Rare earth luminescent materials
Rare earth luminescent materials refer to a new generation of luminescent materials made of rare earth elements as activators or matrix components. There are 4f orbitals in the electron configuration of rare earth element atoms. When 4f electrons radiatively transition from a high energy level to a low energy level, they emit light of different wavelengths.
According to the different excitation light sources, rare earth luminescent materials can be divided into: photoluminescent materials, cathodoluminescent materials, X-ray luminescent materials, electroluminescent materials and so on.
3. Rare earth hydrogen storage materials
Rare earth hydrogen storage material generally refers to rare earth hydrogen storage alloy powder, which is a material that can reversibly absorb and release hydrogen at a lower temperature after adding some second metal to the rare earth metal to form an alloy.
According to the structure type, rare earth hydrogen storage materials can be divided into two categories: AB5 (LaNi5) hydrogen storage alloys and non-AB5 type rare earth hydrogen storage alloys.
4. Rare earth polishing materials
Rare earth polishing material mainly refers to rare earth polishing powder, which refers to a mixed light rare earth oxide powder with cerium oxide as the main component to improve the surface finish of products or parts.
Generally can be divided into low cerium polishing powder, medium cerium polishing powder, high cerium polishing powder. Rare earth polishing powder is widely used in the polishing of optical glass parts, TV kinescope glass bulbs, spectacle lenses, flat glass, oscilloscope tubes and organic glass.
Application fields of rare earth functional materials
Graphite spheroidizing agent, nucleating agent, harmful element control used in cast iron to improve the quality of cast iron.
Glass And Ceramics
Glass： coloring agent, decoloring agent, polishing agent
Ceramics： reduce the chipping of glaze
Improve the tactical performance of weapons can also be used as a lubricant in the nuclear industry.
At present, 90% of the world's oil refinery and cracking units use catalytic cracking agents containing rare earths.
Growth and physiological regulators enhance the ability of crops to resist drought and flood.