cis cis-FarnesolRare 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.