Abstract
When the pressure above 90 MPa was applied to H_2O melt, the (101^^-0) facets appeared in the periphery of (0001) flat face. The corner at which two faces intersect became sharp at 200 MPa but rounded below this value. In the mixture of H_2O and D_2O, facets appeared under atmospheric pressure. In this case, the molar ratio of H_2O to D_2O is dfferent in the melt and the crystal. The effect of pressure and mixing of two isotopes on the faceting was discussed by using tow-level model. As the introduction of present study, moreover, the relation among ΔH, T_m,ΔH/RT_m and the crystal shape was examined considering the bonding mode.
