Formation of LiNbO3 powders and thin films by hydrolysis of metal alkoxides

Crystallization characteristics of LiNbO3 derived from sol-gel

“…This can be overcome by adding a chelating organic ligand into the solution to control the hydrolysis rate of the more reactive alkoxides [-7], and a more fundamental way is to form bimetallic or termetallic alkoxides before hydrolysis [1,2,6]. In the present work, both bimetallic precursor and acid catalysts were used, so enhanced homogeneity was attained even when the hydrolysis process was treated in air.…”

“…In the present study, nitric acid and acetic acid catalysts are respectively introduced in the sol-gel processes for LiNbO3 similar to that described in Yanovsky et al [1] and Hirano and Kato [2]. The influence of catalysts and gelation conditions on crystallization characteristics is discussed in this paper.…”

“…So far, many investigations have been performed on the sol-gel synthesis of LiNbO3 powders and thin films [1][2][3][4]. Usually alcohol solutions of lithium ethoxide, LiOEt, and niobium ethoxide, Nb(OEt)~, were used as precursors, and the effects of the concentration of the precursor solutions on gelation and crystalization were intensively discussed [-1, 2].…”

“…Usually alcohol solutions of lithium ethoxide, LiOEt, and niobium ethoxide, Nb(OEt)~, were used as precursors, and the effects of the concentration of the precursor solutions on gelation and crystalization were intensively discussed [-1, 2]. Yanovskaya et al [1] synthesized bimetallic alkoxide, LiNb(OEt)6, by reacting LiOEt and Nb(OEt)5 in alcohol, and this solution was hydrolysed by an aqueous ammonia solution added dropwise with stirring at 20 ~ During the hydrolysis process clear gel was not formed and precipitation ocurred. Then the precipitate was dried and heated to form crystalline LiNbO3.…”

Nano-heterogeneous structure of (1-x)KNbO3–xSiO2 glasses in the low glass-forming oxide content range 0.05 ≤ x ≤ 0.3

“…Moreover, the only non-centrosymmertic phase in the system under investigation is ferroelectric KNbO 3 which is known to manifest its ferroelectric properties only if perfect perovskite-like crystalline structure exceeds the size of~10 × 10 × 10 nm [20]. As far as KNbO 3 size exceeds mentioned above sizes during glass crystallization, much larger SHG activity is usually observed in similar substances including those on the base of amorphous LiNbO 3 [3,21] Certainly we can assume that ordering processes take place in the nanoinhomogeneities under heat treatment of KNS glasses. However (Fig.…”