Adsorption of barium atoms on silicon carbide

Adsorption of barium atoms on the C- and Si-faces of the 3$C$- 6$H$- and 4$H$-SiC polytypes is considered within the scope of the Haldane–Anderson model. Charge transfer from Ba atoms to the substrate is analyzed with the account of the band and local states of the adsorbed system. The ionic and metallic con-tributions to the adsorption energy are estimated. To improve some obtained results surface molecule model is used.