Growth and properties of Mg2SiO4 single crystals

Abstract Large single crystals of Mg 2 SiO 4 (forsterite) up to 25 mm in maximum diameter and 60 mm long were grown by the Czochralski method. The optically homogeneous specimens of about 15 X 15 x 20 mm 3 in size were obtained from fabricating the as-grown boules. The main imperfections included in the crystals were minute gas bubbles located about the central portion of the crystals. Chemical analyses showed that the single crystals contained nonstoichiometric excess of Mg ions in the range of 0.7 to 2.4 mol%. The major impurity was several hundred weight ppm of Fe. Contamination of the crystals with the crucible irridium has been proved to be about 17 weight ppm by the neutron activation analysis.