Naslov
Sol-gel synthesis and characterization of Nb2O5 powders

Autori
Ristić, Mira ; Popović, Stanko ; Musić, Svetozar

Izvornik
Materials letters (0167-577X) 58 (2004), 21; 2658-2663

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Sol-gel; Nb2O5; XRD; DTA/TGA; FT-IR; SEM

Sažetak
Nb2O5 powders were prepared by the sol-gel procedure. Nb(OC2H5)5 dissolved in ethanol was (a) rapidly hydrolysed by adding a concentrated NH4OH solution, or (b) slowly hydrolysed by adding a small amount of H2O. The Nb2O5 powders were characterized by XRD, DTA / TGA, FT-IR spectroscopy and SEM. The initial Nb2O5 powders were amorphous. Upon heating at 300 oC of the amorphous powder obtained by the method (a) there was no change as shown by XRD, whereas the amorphous powder obtained by the method (b) and also heated at 300 oC contained Nb2O5 (TT-phase) plus an amorphous fraction. The amorphous powders heated at 500 oC contained Nb2O5 (TT-phase), whereas at 650 oC the Nb2O5 (T-phase) was obtained. Crystallite sizes were determined using the Scherrer method. The agreggates of nanosized Nb2O5 were present in amorphous Nb2O5 precursors and upon their heating at 300 oC, whereas upon heating at 650 oC a porous interconnected microstructure was formed in both preparations, (a) and (b), as shown by SEM.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA