Flux growth of straw-like rutile monocrystals



Millimetric straw-like rutile monocrystals were grown by the flux growth technique. A suitable mixture of flux (MoO3, V2O5, Li2CO3) and amorphous TiO2 gel was slowly cooled down to 750°C from 1250°C or 1350°C. The best yields of straw-like rutile were obtained with a nutrient/flux ratio and a cooling rate in the range 0.015-0.006 and 1.8-1.9 K h-1, respectively. The hollowed crystals were characterized by powder and single-crystal X-ray diffraction, scanning electron microscopy, microthermometry, and µ-Raman spectroscopy. As for skeletal crystal, the formation of axial canals in rutile is attributed to a lack of nutrient due to the viscosity of the melt and the high growth rate along [001]. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)