Zirconia-Alumina-ITO Nanolaminates for Transparent, Conducting, Transformation-Toughening Coatings
Abstract
The revised objective of the proposed research was investigate room temperature interface alloy and compound formation in zirconia-bearing pseudobinary nanolaminate systems. Two model systems with the same nominal architecture but extremes in chemical reactivity between constituents were compared: zirconia-alumina (immiscible) and zirconia-yttria (completely miscible). The results showed that in zirconia-alumnina nanolaminates, layers were separate entity and with incoherent interfaces. The phase present in the zirconia layers was governed by the finite crystal size effect. In zirconia-yttria nanolaminates, an interfacial reaction between constituents completely obliterated separate layers. The reaction product, yttria-stabilized cubic zirconia, grew in the form of needle-like crystallites. These results demonstrate that coatings consisting entirely of interface reaction products can be fabricated if the bilayer spacing is small enough in a system in which the bulk equilibrium phase diagram predicts reaction between oxide components. An important question concerns the properties of an interface in a nanolaminate in which there are chemical but not physical driving forces for reaction of bilayer components during deposition, i.e., no predisposition towards heteroepitaxy or pseudomorphism. A model for this behavior is provided by the ZrO2-TiO2 system. Study of zirconia-titania nanolaminates was initiated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 15, 2000
- Accession Number
- ADA385818
Entities
People
- Carolyn R. Aita
Organizations
- University of Wisconsin–Milwaukee