Nucleation and Growth of Order in Cu(3)Au (111) Films

During epitaxial growth of (111) face-centered cubic crystal films, such as disordered $\rm Cu\sb3Au,$ there are two possible ways that successive layers can be laid down, leading to two types of stacking domains. However, a small vicinal miscut $(0.5\sp\circ {-}1\sp\circ )$ of the crystal surface introduces step edges that change nucleation preferences of the domains, resulting in one being preferred over the other by ratios up to 700:1. Fifteen samples were measured and this preference has been found to depend systematically and strongly on the magnitude and direction of the sample miscut. A qualitative RHEED study confirms that a preference for one of the stacking senses is present after deposition of a few monlolayers of $\rm Cu\sb3Au.$ The observed behavior of the film can be explained by a model in which Cu and Au atoms minimize their number of Nb nearest neighbors when growing over the Nb step edges. This represents both a discovery of a new phenomena in epitaxial nucleation and a technique for the production of improved epitaxial films.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Bonham, Scott William

Contributors dc:contributor

• C. Peter Flynn

• Engineering, Materials Science

Language dc:language

eng

Identifier

(MiAaPQ)AAI9737056

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/80643