HIGH-RESOLUTION ELECTRON-MICROSCOPY OF PRESSURIZED AL68PD23MN9 ICOSAHEDRAL PHASE

Pressure-induced irreversible amorphization and crystallization were definitively observed at the atomic scale, using high-resolution electron microscopy, in the uniaxially compressed icosahedral phase of Al68Pd23Mn9, at pressures from 10 to 20 GPa at ambient temperature. The pressure-amorphized state was found to comprise a random packing of atomic clusters. The pressure-induced crystalline phase was identified to have a fee structure with a lattice parameter a = 0.38 nm which is not an approximant of the icosahedral phase of Al-Pd-Mn.