SEGREGATION EFFECTS IN THIN-FILMS

Atomic segregation and second-phase precipitation at surfaces and interfaces have a strong influence on many properties of bulk materials. Because these regions are different in chemistry and sometimes in lattice structure from the bulk, they can exert a pronounced influence on thin film properties, more so than in bulk materials owing to the large extent of the segregated and/or precipitated zones compared with the film thickness. Some of the similarities and the contrasting features of the segregation phenomena observed between thin films and bulk materials are noted. The thermodynamic aspects and diffusion kinetics which control segregation, the surface reactions and the formation of surface compounds in thin films are discussed. The influence of segregation and interfacial reactions on thin film properties and common experimental methods of studying segregation are briefly reviewed with selected examples. © 1979.