The rare earth hexaborides have extremely excellent field emission properties that have been intensively studied within the past decades since the discovery of thermionic emission properties of LaB6 by Lafferty. They are potential for excellent electron emitters that can be widely used.

The group of Prof. Guanglei Zhang published an article titled "Effects of pressure on electronic structure and magnetic properties of cerium boride CeB6 cathode crystalline material", investigated the thermal stabilities, electronic structures, magnetic properties and the charge transfers of the rare earth Cerium hexaborides CeB6^[1].

Figure 1 Illustrations of crystal structure^[1]

The analyzing results show that the Cerium Boride CeB6 under 1?GPa has relatively lower total energy of ?1526.1675?eV than that of Cerium Boride CeB6 under 0?GPa. The Cerium Boride CeB6 under 1?GPa has band gap of 1.305?eV, which is 0.152?eV lower than that of the Cerium Boride CeB6 under 0?GPa of 1.457?eV. The work function of electrons is also decreased by 0.465?eV. There are three energy valleys in the bottom conduction band and four energy peaks in the top valance band, the emission efficiency should be high. The quantity of electrons that are readily to be motivated for emission is larger for Cerium hexaborides CeB6 under 1?GPa. The total partial density of states for Cerium Boride CeB6 under different isostatic pressure is mainly formed by B p electrons. The B should play more important role in electron emission for CeB6 under 1?GPa. The CeB6 under different isostatic pressure is ferromagnetic material. The combination bond effect between B is enhanced for Cerium Boride CeB6 under 1?GPa.

Reference

[1] Effects of pressure on electronic structure and magnetic properties of cerium boride CeB6 cathode crystalline material. doi:10.1016/j.rinp.2019.102444