Heat-Treatment-Induced Evolution of the Mesostructure of Finely Divided Y3Al5O12 Produced by the Sol-Gel Method.

Autor: Simonenko, E. P., Simonenko, N. P., Kopitsa, G. P., Almásy, L., Gorobtsov, F. Yu., Sevastyanov, V. G., Kuznetsov, N. T.
Zdroj: Russian Journal of Inorganic Chemistry; Jun2018, Vol. 63 Issue 6, p691-699, 9p
Abstrakt: A method was developed for the low-temperature sol-gel synthesis of one of the most popular components of functional and structural materials—nanostructured yttrium aluminum garnet Y3Al5O12—using precursors from the class of alkoxoacetylacetonates produced from the corresponding acetylacetonates. It was determined that increasing duration of heat treatment of yttrium-aluminum-containing xerogen in air to 6 h reduces the crystallization temperature of the Y3Al5O12 phase from 920-930 to 750-800°C, which was confirmed by IR spectroscopy and X-ray powder diffraction analysis. The microstructure of nanocrystalline yttrium aluminum garnet obtained at 800°С was studied; it was found that the size of crystallites is 30-40 nm, the size of particles is 30-50 nm, and the size of pores is 20-30 nm. Small-angle neutron scattering demonstrated that, in the powders synthesized at 700-800°C, there is structural ordering of the short-range type, whereas in the nanocrystalline samples heat-treated at a higher temperature (850°С), there is no such ordering. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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