Some Properties of Magnesium Fluoride crystallized from the Melt

This is the authors' abstract. We don't add key points for this paper.

Magnesium fluoride crystals can be grown in vacuo using the Stockbarger technique. The melting point is 1255 ± 3°C. The crystal structure is of the tetragonal SnO 2 type, with lattice constant a = 4.621 ± 0.001 Å and axial ratio 1: 0.6601 ± 0.0001 giving c = 3.050 Å at 18°C. The density is 3.1766 ± 0.0002 g cm -3 at 18°C. MgF 2 is a uniaxial positive crystal, and the refractive indices are given for the ordinary and extraordinary rays at various wavelengths in the visible spectrum. The transparent region extends from 1100 Å to 1360 cm -1 . Infra-red reflectivity begins to rise at about 620 cm -1 , and peaks around 500 cm -1 . The mean dielectric constant is m = 5.26.