Mechanical synthesis of nanostructured Y2Ti2O7 pyrochlore oxides

Abstract

Pyrochlore-type Y2Ti2O7 powders were successfully synthesized by mechanical milling. Nanosized powders of Y2O3 and TiO2 are milled to form an amorphous mixture of Y2Ti2O7 containing a small quantity of crystallized fluorite structure and initial constituents. The desired fully crystallized pyrochlore phase is obtained from this mixture through heat treating at 900 °C. In situ X-ray Diffraction by Synchrotron radiation investigations reveal that this transformation takes pace through a first step of crystallization into a fluorite-like structure at 800 °C. The formation of the pyrochlore structure occurs around 900 °C. The obtained product is a nanostructured pyrochlore powder of which can be integrated in the manufacturing process of oxide dispersion strengthened steels.