Densification and crystallization of zirconia thin films prepared by sol-gel processing

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:10116785

Schwartz, R W; Voigt, J A; Buchheit, C D; Boyle, T J

We have investigated the effects of precursor nature and heat treatment schedule on the densification and crystallization behavior of sol-gel derived zirconia thin films. Precursor solutions were prepared from n-propanol, zirconium (IV) n-propoxide, and either acetic acid, or 2,4-pentanedione (acac) and water additions. By controlling the ligand type and ligand-to-metal ratio, we were able to prepare films which displayed significant differences in densification behavior. We attribute the dissimilarity in densification to variations in the nature of the as-deposited films, as influenced by ligand type and concentration. While the acac- derived film was a physical gel, (i.e., a physical aggregation of the oligomeric species), the acetic acid-derived film, which exhibited less consolidation, was a chemical gel that could not be redissolved in the parent solvent. Films prepared with large acac/metal ratios and small water additions exhibited minimal crosslinking at 25{degree}C, displayed the greatest consolidation ({approximately}86% shrinkage) and the highest refractive index (n = 2.071) when heat treated. These results indicate the importance that M-O-M bonds (crosslinks) formed at low temperature can have on densification behavior. We also report on the effects of heat-treatment schedules and ramp rates on densification behavior. All of the films of the present study crystallized into the cubic phase, at temperatures ranging from {approximately}400{degree}C to greater than 700{degree}C, depending on the heating rate.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 10116785
• Report Number(s): SAND--93-0975C; CONF-931142--5; ON: DE94005573; BR: GB0103012
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202
CRYSTALLIZATION
DENSITY
SOL-GEL PROCESS
STRUCTURE AND PHASE STUDIES
THIN FILMS
ZIRCONIUM OXIDES