The similarities of geochemical properties and behaviors among rare earth elements are similar in atomic structure, ionic radius and chemical properties.
1. the atomic structure is similar to that of electronic configuration: the rare earth elements are lanthanides in the periodic table (including lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium and gadolinium). This similarity between atomic structure and electronic configuration makes rare earth elements show high similarity in chemical properties.
2. Similar ionic radii: The ionic radii of rare earth elements are similar, which means that they can replace each other in minerals and form similar mineral phases. This similarity of ion radii makes rare earth elements have similar geochemical behaviors, for example, they can exchange ions and migrate at similar rates.
3. Similarity in chemical properties: Rare earth elements have similar chemical properties, and they all have small electronegativity, so they are easy to lose outer electrons and form positive ions. Therefore, rare earth elements usually behave as positive ions in chemical reactions and have similar chemical activity. This similarity of chemical properties makes rare earth elements show similar reaction behavior in geochemical process.
application of rare earth elements:
1. permanent magnet materials: neodymium, promethium, samarium, europium, gadolinium and other rare earth elements have excellent magnetic properties and can be used to prepare high-performance permanent magnet materials. These rare earth permanent magnet materials have high magnetic energy product, high coercivity and high permeability, and are widely used in electronics, information, aerospace, energy and other fields.
2. luminescent materials: rare earth elements can emit unique fluorescence and phosphorescence, which is caused by their f-f transition energy levels. Rare earth luminescent materials can be used in fluorescent lamps, displays, lasers, lighting and other fields, and have the advantages of high efficiency, energy saving and environmental protection.
3. Catalytic materials: Rare earth elements have excellent catalytic performance and can be used in petrochemical, environmental protection, automobile and other fields. For example, the automobile exhaust catalyst added with rare earth elements can effectively purify harmful substances in automobile exhaust.
4. Optical glass and optical fiber: Rare earth elements can absorb and transmit light energy, so they can be used to prepare optical glass and optical fiber. These materials are widely used in communication, information processing and other fields.
5. Medical field: Rare earth elements are also widely used in the medical field, such as preparing drugs and therapeutic reagents. In addition, some rare earth elements can also be used to prepare medical equipment and diagnostic reagents.