On the Possibility of Preparing Fine-Particle Barium Zirconate by Hydrothermal Synthesisстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация:Abstract—The possibility of preparing fine-particle BaZrO3 by hydrothermal synthesis was examined. The
samples prepared using three different starting mixtures were characterized by x-ray diffraction, thermogravimetry,
and scanning and transmission electron microscopy techniques. By dissolving solid Ba(NO3)2 in a 0.25 M
ZrO(NO3)2 solution (pH 1.5), nanocrystalline powder of the stable polymorph M-ZrO2 was obtained (particle
size d = 8–10 nm), independent of the Ba(NO3)2 : ZrO(NO3)2 ratio. Hydrothermal treatment of a ZrO(OH)2 gel
in neutral (pH 7.0) and ammonia (pH 11.0) media in the presence of Ba(NO3)2 yielded only the metastable
phase T-ZrO2 (d = 10–12 nm), whereas treatment under similar conditions with no Ba(NO3)2 in solution
resulted in a mixture of M- and T-ZrO2. The formation of microcrystalline BaZrO3 (d = 2–5
mm) from a
ZrO(OH)2 gel was observed only in a high-pH Ba(OH)2 solution (pH 13.0). Attempts to obtain BaZrO3 by boiling
an amorphous ZrO(OH)2 gel at 378 K at atmospheric pressure in a high-pH Ba(OH)2 solution (pH 13.0) for
45 min with the use of microwave heating were unsuccessful: the solid phase consisted of x-ray amorphous
ZrO(OH)2.