CRYSTAL-GROWTH OF THE HIGH-PRESSURE PHASE OF MG2SN

Phase relations in the Mg2Sn-Sn system were studied by differential th ermal analysis at a pressure of 5.8 GPa and temperatures up to 1100 de grees C. A schematic p,T diagram for Mg2Sn is presented. Single crysta ls of the high-pressure phase of Mg2Sn were obtained by growth from a molten solution under high pressure. Crystal data for Mg,Sn II were de termined using a Buerger precession X-ray camera. The phase Mg2Sn II c rystallizes with hexagonal unit cell, a=13.19+/-0.01 Angstrom, c=13.28 +/-0.01 Angstrom, c/ a=1.006, D-m=4.1+/-0.2 g cm(-3), z=30, D-c=4.17 g cm(-3), space group P3c1 (no. 158) or P (3) over bar c1 (no. 163).