Structural investigations of the amorphous alloyAl30Ge70under high pressure

The structural behavior of the amorphous phase ${\mathrm{Al}}_{30}$ ${\mathrm{Ge}}_{70}$, obtained by pressure quenching, has been investigated under pressure by in situ energy dispersive x-ray diffraction (EDXD) using synchrotron radiation. At p≊5 GPa there is a reversible transition from the amorphous state to a crystalline state with simple hexagonal (sh) structure. This γ phase is stable up to 47 GPa. At this pressure a transition to a hexagonal closed-packed structure takes place. The behavior of ${\mathrm{Al}}_{30}$ ${\mathrm{Ge}}_{70}$ under pressure is discussed in connection with structural transformations of group-IV elements and III-V compounds. © 1996 The American Physical Society.