Formation of Hexagonal Closed Packed Metas-Table Phase during the Solidification of Ag-20 at% Ge Melt under High Pressure

The metastable hexagonal closed packed phase with lattice parameters a=0.289 8 nm, c=0.470 8 nm and c/a=1.625 has been obtained by melt quenching of Ag-20 at% Ge alloy under high pressure. The application of a pressure of 7.2 GPa to melt quenching induced a decreasing of cooling rate in magnitude of four orders for the formation of the hexagonal phase.