Role of the oriented attachment mechanism in the phase transformation of oxide nanocrystals
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Data
2007-01-01
Autores
Ribeiro, Caue
Vila, Cristiane
de Matos, Jose Milton Elias
Bettini, Jefferson
Longo, Elson [UNESP]
Leite, Edson R.
Título da Revista
ISSN da Revista
Título de Volume
Editor
Wiley-Blackwell
Resumo
Bottom-up methods to obtain nanocrystals usually result in metastable phases, even in processes carried out at room temperature or under soft annealing conditions. However, stable phases, often associated with anisotropic shapes, are obtained in only a few special cases. In this paper we report on the synthesis of two well-studied oxides-titanium and zirconium oxide-in the nanometric range, by a novel route based on the decomposition of peroxide complexes of the two metals under hydrothermal soft conditions, obtaining metastable and stable phases in both cases through transformation. High-resolution transmission electron microscopy analysis reveals the existence of typical defects relating to growth by the oriented attachment mechanism in the stable crystals. The results suggest that the mechanism is associated to the phase transformation of these structures.
Descrição
Palavras-chave
crystal growth, nanostructures, oriented attachment, phase transitions
Como citar
Chemistry-a European Journal. Weinheim: Wiley-v C H Verlag Gmbh, v. 13, n. 20, p. 5798-5803, 2007.