TY - JOUR
T1 - Interrelationship between Densification, Crystallization, and Chemical Evolution in Sol‐Gel Titania Thin Films
AU - Keddie, Joseph L.
AU - Braun, Paul V.
AU - Giannelis, Emmanuel P.
PY - 1994/6
Y1 - 1994/6
N2 - The mechanisms contributing to densification during non-isothermal heat treatments in sol-gel titania films have been studied. At low temperatures, shrinkage is attributed to condensation reactions between hydroxyls located primarily within the oxide skeleton. At higher temperatures, densification is due to both continued condensation between surface hydroxyls and structural relaxation. Shrinkage stops when films attain a level of crystallinity corresponding to the percolation threshold. At conventional rates, densification is delayed by faster heating; however, at very fast heating rates provided by rapid thermal annealing (8000°C/min), condensation is highly arrested and densification is faster. Similarly, the onset of crystallization increases with conventional heating rates, but crosses over to a lower temperature with rapid thermal annealing.
AB - The mechanisms contributing to densification during non-isothermal heat treatments in sol-gel titania films have been studied. At low temperatures, shrinkage is attributed to condensation reactions between hydroxyls located primarily within the oxide skeleton. At higher temperatures, densification is due to both continued condensation between surface hydroxyls and structural relaxation. Shrinkage stops when films attain a level of crystallinity corresponding to the percolation threshold. At conventional rates, densification is delayed by faster heating; however, at very fast heating rates provided by rapid thermal annealing (8000°C/min), condensation is highly arrested and densification is faster. Similarly, the onset of crystallization increases with conventional heating rates, but crosses over to a lower temperature with rapid thermal annealing.
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U2 - 10.1111/j.1151-2916.1994.tb09761.x
DO - 10.1111/j.1151-2916.1994.tb09761.x
M3 - Article
AN - SCOPUS:0028459860
SN - 0002-7863
VL - 77
SP - 1592
EP - 1596
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 6
ER -