Crystal habit for upconversion laser crystal of BaY2F8

BaY2F8 crystals had a relatively low symmetry, and its XRD data showed that those strong diffractions occurred in a narrow angle range, so it was difficult to orientate the single crystals of BaY2F8. In this paper, based on the structure characteristics and XRD data, the crystal habit of BaY2F8 was analyzed. The strong bond in crystal structure of BaY2F8 was Y-F2-Y, which stretched to the shape of chain along the direction of [001]. And this was an advantaged direction for the crystal growth. The steady shapes of BaY2F8 were composed of rhombic prism {130} and {021}. The crystal showed an axial habit in the direction of [001]. The analysis of the crystal slice obtained by temperature gradient technique verified the above conclusion. The BaY2F8 crystal was grown by compulsive methods such as Czochralski method.