Emission energy barriers of scandate surfaces with adsorbed Ba and Ba-O using Density Functional Theory

摘要

Density functional theory was used to calculate the surface electron emission barriers for the stable (011) and (111) surfaces of bixbyite Sc_20_3 in the presence of adsorbed Ba and Ba-O. A low surface barrier of 1.21 eV for a defected BaO monolayer on Sc_2O_3 (011) was found to be thermodynamically stable. This result provides a straightforward explanation of low effective work function measurements obtained for scandate cathodes.