Processing and phase stability of metal carboxylate-derived barium-yttrium-copper oxide thin films

The processing and phase stability of Ba$\sb2$YCu$\sb3$O$\sb{\rm 7-x}$ High T$\sb{\rm c}$ thin films are seen to be critical aspects of the successful fabrication of this material. Metal neodecanoates of barium, yttrium, and copper were synthesized and mixed into a homogeneous, precipitate-free solution, which was spin-cast onto ZrO$\sb2$ coated silicon wafers. A minimum heat treated temperature of 725$\sp\circ$C in N$\sb2$ was needed to decompose the BaCO$\sb3$ present in the films. A phase map of the stability of Ba$\sb2$YCu$\sb3$O$\sb{\rm 7-x}$ as a function of heat treatment temperature and ambient showed both the upper and lower temperature boundaries to increase with decreasing P$\sb{\rm O2}$, with the higher temperature boundary truncated at temperatures $>$800$\sp\circ$C from interdiffusion of the films with the substrate. The high temperature decomposition mechanism for the high P$\sb{\rm O2}$ condition was seen to be nucleation of BaCuO$\sb2$, followed by formation of BaY$\sb2$CuO$\sb5$, the accelerated formation of which was attributed to the small grain size ($$90 K was accounted for by the presence of the weak links in the film microstructure.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Ceramic Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Davison, William Watson

Contributors dc:contributor

• Buchanan, Relva C.

• Engineering, Materials Science

Statement dc:rights

• Copyright 1990 Davison, William Watson

Language dc:language

eng

Identifier

AAI9021668
(UMI)AAI9021668

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/19284