Structure and Phase Transformation of Nanocrystalline and Amorphous Alloy Thin Films

The systematic study on the structure and morphology of Ag-Si alloy thin films shows nanocrystalline Ag clusters embedded in amorphous Si matrix for samples of different compositions and thicknesses. Ag cluster sizes increase from 2.5 nm to 3.5 nm as annealing temperature increases from room temperature to 500°C, and the cluster densities decrease accordingly from 2.5x10 4/mum2 to 7.6x103/mum 2. This phenomenon can be explained by grain growth and Ostwald ripening in which big clusters grows bigger at the expense of smaller clusters. The Ag clusters remain relatively stable under annealing; HREM images show crystalline structure at 500°C, which is different from Ag clusters supported on other substrates. TEM observation shows that Ag clusters are embedded inside the amorphous Si matrix, which explains their relative stability at high temperatures.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Science and Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Chen, Hao

Contributors dc:contributor

• Zuo, Jian-Min

• Engineering, Metallurgy

Language dc:language

eng

Identifier

(MiAaPQ)AAI3242814

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/82785