Processing and phase stability of metal carboxylate-derived barium-yttrium-copper oxide thin films
type: CreativeWork
description: 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 ($$90 K was accounted for by the presence of the weak links in the film microstructure.
abstract: The processing and phase stability of Ba$\sb2$YCu$\sb3$O$\sb{\rm 7-x}$ High T$\sb{\rm c}$ thin films are seen to be critical aspects of the successful fabrication of this material. Metal neodecanoates of barium, yttrium, and copper were synthesized and mixed into a homogeneous, precipitate-free solution, which was spin-cast onto ZrO$\sb2$ coated silicon wafers. A minimum heat treated temperature of 725$\sp\circ$C in N$\sb2$ was needed to decompose the BaCO$\sb3$ present in the films. A phase map of the stability of Ba$\sb2$YCu$\sb3$O$\sb{\rm 7-x}$ as a function of heat treatment temperature and ambient showed both the upper and lower temperature boundaries to increase with decreasing P$\sb{\rm O2}$, with the higher temperature boundary truncated at temperatures $>$800$\sp\circ$C from interdiffusion of the films with the substrate. The high temperature decomposition mechanism for the high P$\sb{\rm O2}$ condition was seen to be nucleation of BaCuO$\sb2$, followed by formation of BaY$\sb2$CuO$\sb5$, the accelerated formation of which was attributed to the small grain size ($$90 K was accounted for by the presence of the weak links in the film microstructure.
author: Davison, William Watson
language: eng
keywords: Engineering, Materials Science
date published: 2011-05-07T12:02:45Z
date modified: 2026-07-22T22:25:12Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/19284