The electronic structure and work functions of single crystal LaB6 typical crystal surfaces

摘要

The crystal electronic structure and work functions of single crystal LaB6 typical crystal surfaces were systematically studied. The electronic structure calculation shows that the LaB6 have metallic property and the large density of state near the Fermi level of LaB6 is mainly composed of La 5d, 6s and B 2p. The work functions of typical (100), (110), (111), (210), (211), (310) surfaces calculation shows that the (100) surface with highest La concentration and regular symmetric surface structure, providing a lowest work function 2.40eV and (110), (111), (210), (211), (310) work functions are 2.43 eV, 2.68 eV, 2.51 eV, 2.54 eV, 2.52 eV, respectively. The thermionic emission test results show that the effective work functions of the single crystal LaB6 on (100), (110), (111), (210), (211), (310) surfaces are 2.66 eV, 2.73 eV, 2.78 eV, 2.69 eV, 2.72 eV, 2.71 eV, respectively. Thus, the actual performance is basically accordant with the calculated value and the (100) surface of LaB6 single crystals should provide better emission performance in practical application. (C) 2017 Elsevier Ltd. All rights reserved.