title: First principles study of gallium cleaning for hydrogen-contaminated α-Al2O3(0001) surfaces.
abstract: The use of gallium for cleaning hydrogen-contaminated Al2O3 surfaces is explored by performing first principles density functional calculations of gallium adsorption on a hydrogen-contaminated Al-terminated α-Al2O3(0001) surface. Both physisorbed and chemisorbed H-contaminated α-Al2O3(0001) surfaces with one monolayer (ML) gallium coverage are investigated. The thermodynamics of gallium cleaning are considered for a variety of different asymptotic products, and are found to be favorable in all cases. Physisorbed H atoms have very weak interactions with the Al2O3 surface and can be removed easily by the Ga ML. Chemisorbed H atoms form stronger interactions with the surface Al atoms. Bonding energy analysis and departure simulations indicate, however, that chemisorbed H atoms can be effectively removed by the Ga ML.
authors: Research School of Computer Science, College of Engineering and Computer Science, the Australian National University, Canberra ACT 0200, Australia. ruiy@uow.edu.au
authors: Rui
authors: R
authors: Yang
authors: Alistair P
authors: AP
authors: Rendell