Surface properties of rare-earth metals and the effects of their substitutional doping on work function of the W(110) surface

The surface energy and work function of rare-earth metals (from La to Lu) are studied by the first principles calculations. The obtained values are in good agreement with available experimental data. Motivated by enhanced thermionic emission performance resulting from low work function, we substitutionally doped the rare-earth atoms on W(110) surface to improve the work function. The results show that rare-earth atoms doping can significantly reduce the work function of the W(110) surface, and Eu, Pr and Nd are the three best candidates for work function reduction.