Direct Evidence for Amorphization of Pure Gallium by Low-Temperature Ion Irradiation

By combining low-temperature ($T<\mathrm{}10\mathrm{}$ K) heavy-ion bombardment (275-keV ${\mathrm{Ar}}^{+}$, 250-keV ${\mathrm{Ne}}^{+}$) with an in situ low-temperature electron-diffraction technique, for the first time direct evidence could be provided that ion irradiation can result in a complete amorphization of gallium, i.e., of a pure metal without a second component stabilizing the amorphous phase. The results can be interpreted in terms of a spike model and are in close analogy to those found by vapor quenching onto a liquid-helium-cooled substrate.