Published online by Cambridge University Press: 26 January 2011
Shape-controlled CaF2 and sapphire crystals were grown by a micro-pulling-down (μ-PD) method and the crystallinities were investigated. By the μ-PD method with crucibles which have special configurations, circular tube-shaped CaF2 crystal, square tube-shaped CaF2 crystal and square tube-shaped sapphire crystal with high transparency were obtained. The grown crystals indicated a single phase of CaF2 and Al2O3 in the XRD measurements. X-ray rocking curve of square tube-shaped sapphire indicated the crystal has no mosaic structure in the crystal and it has high crystallinity comparable to crystals grown by Cz method.