Percolation model for elastic softening in intermetallic compounds during solid-state amorphization

By using isobaric-isothermal molecular dynamics and an n-body effective potential, we show that the amorphization of ${\mathrm{NiZr}}_2$, mediated by chemical disorder, is preceded by an elastic softening and begins at the percolation threshold of the strain distortion regions associated with the antisite defects. The percolation model provides a unified description of the elastic softening and loss of crystalline order in intermetallic compounds resulting from irradiation or hydrogenation.