Crystallization of metastable tetragonal zirconia from the decomposition of a zirconium alkoxide derivative

The formation of refractory oxide coatings on Nicalon™ fiber by sol-gel process

“…A sufficient decrease in the number of these vacancies due to heat treatment in the presence of oxygen facilitates the instability in the metastable tetragonal phase and the following t!m transition. 15 An analogous phenomenon was observed not only for monolithic ceramic specimens but also within the CVD ZrO 2 coating on SiC fiber by Li et al 18 Besides abovementioned factors the influence of support, namely, SiC fiber and also free carbon presenting as an impurity in coating on the mechanism of tetragonal ZrO 2 phase nucleation must be taken into consideration. Quite different behavior is observed during the formation of alumina coating.…”

Raman study of yttria-stabilized zirconia interfacial coatings on Nicalon™ fiber

“…As a consequence, the t → m transformation is observed. 15,16 Earlier it was proposed, 2-4 that carbon particles might be a factor that can cause t-ZrO 2 stabilization. Consumption of carbon during the oxidation tests could be another plausible reason for the t → m phase transformation in the coating exposed to air.…”

“…[15][16][17] It was shown that the stabilization of t-ZrO 2 at low temperatures can be governed by several factors such as the crystallite size effect, the presence of stabilizers, the presence of impurities, the structural similarities between the tetragonal phase and the amorphous phase of precursor. 18(and refs therein) Besides named factors, the influence of supports on the mechanism of tetragonal ZrO 2 phase nucleation (for coatings and films) must be taken into consideration too 19 .…”

MOCVD of Zirconia Thin Films by Direct Liquid Injection Using a New Class of Zirconium Precursor

“…Although titanium alkoxy/β-diketonates are well documented in the literature, [16,17] the only analogous Zr compound thus far reported is Zr(O t Bu) 2 (acac) 2 , used in the sol-gel deposition of ZrO 2 . [18] This approach aims to combine the advantages of high ambient stability, associated with coordinatively saturated zirconium β-diketonates, with the lower thermal stability and increased volatility of Zr(OR) 4 compounds, and in this communication we report the growth of ZrO 2 films at reduced temperature by MOCVD using the novel precursors Zr(OR) 2 (thd) 2 (R = i Pr, t Bu).…”