Chemical ordering of alloy surfaces: Low-index versus vicinal surfaces - art. no. 125418

Some A(3)B fee alloys undergo a chemical order-disorder phase transition. D uring the ordering process, four types of domain appear within the bulk, se parated by antiphase boundaries (APB's). As for chemical ordering in the pr esence of a surface, scanning tunneling microscopy and He diffraction studi es consistently show a contrasting behavior between vicinals, where APB's e merge at the surface, and low-index surfaces, where no APB's emerge. These differences emphasize the role of the step density in surface chemical orde ring.