Nano Rare-earth Materials

Nano Rare-earth Materials List

Rare earth elements have special atomic structure with many unpaired electrons in the inner 4f orbital, high atomic magnetic moment and extremely rich electron energy levels. Rare earth elements can react with almost all elements to form compounds with multi-valence state and multi-coordination number. Nanomaterials refer to single crystal or polycrystal with grain size less than 100 nm, which has excellent properties such as high strength and hardness, low density, low elastic modulus, high resistance and low thermal conductivity. With the advantages of small size effect, surface effect, quantum size effect and macroscopic quantum tunneling effect, nanomaterials exhibit many unique light, electricity and magnetism properties that are not available in conventional materials. Combing the properties of rare earth elements and nanomaterials, nano rare-earth materials have been the focus of the research.

Figure 1. Structure of a representative nano rare-earth material Y2O3.

Applications:

• Catalysis field: Due to the surface effect, volume effect and quantum size effect, nano rare-earth materials have good catalytic activity and are widely used in the field of catalysis. Nano rare-earth materials are generally used in petroleum catalytic cracking and purification treatment of automobile exhaust.

Figure 2. An example of nano rare-earth materials applied in catalysis field.

• Optical field: The particle size of nano rare-earth materials is usually smaller than the wavelength of excitation or emission light waves. Therefore, the light field can be approximately uniform within the particle range, and the microcavity effect caused by the confined effect of light waves does not exist. Based on their excellent optical properties, nano rare-earth materials can be used in the design of display screens, organic luminescent materials, anti-infrared materials, sunscreens and the others.
• The others: In addition to the above fields, nano rare-earth materials have been widely used in many other fields, such as biomedical field, hydrogen storage field, environmental protection field, lubrication field, magnetic recording field and the others.

Classification:

There are many kinds of nano rare-earth materials, including nano rare-earth powder materials, nano rare-earth ceramics, nano rare-earth magnetic materials and the others.

• Nano rare-earth powder: Nano rare-earth powder is not only a kind of new material, but also a kind of raw material. The methods of preparing nano rare-earth powder materials in laboratory and industry include sol-gel method, precipitation method, hydrolysis method, combustion method, thermal decomposition method and the others.
• Nano rare-earth ceramic: Nano rare-earth ceramic is one of the important components of nano rare-earth materials. Nano rare-earth ceramic not only has the properties of nano ceramic, but also has its own characteristics, such as oxygen storage, ion conductivity and the others.
• Nano rare-earth magnetic material: Nano rare-earth magnetic material is a new generation of magnetic material with the characteristics of small size, single magnetic domain structure, high coercive force, small volume and high reliability.
• The others: Nano rare-earth materials also include nano rare-earth film, nano rare-earth catalyst, nano rare-earth hydrogen storage materials and the others.

References

1. Gaboriaud, R.J, Paumier, et al. Disorder–order phase transformation in a fluorite-related oxide thin film: In-situ X-ray diffraction and modelling of the residual stress effects[J]. Thin Solid Films, 2016.
2. Perrier A, Keller M, Caminade A M, et al. Efficient and recyclable rare earth-based catalysts for Friedel–Crafts acylations under microwave heating: dendrimers show the way[J]. Green Chemistry, 2013, 15.