Thermal-spike theory of sputtering: The influence of elastic waves in a one-dimensional cylindrical spike

The sputtering yield (Y) from a thermal spike is calculated using an extended version of the standard thermal-spike theory, which includes the transport of mass, a more realistic heat capacity, and melting. The results show that introducing the heat of melting and using a heat capacity that accounts for the “equipartion theorem” at low temperatures has a significant influence on the sputtering yield at low deposited energies $\mathrm{}(dE/dX).$ The transport of mass within the spike becomes relevant at large deposited energies, where the thermal pressure in the hot core of the spike gives rise to an elastic wave which expands and cools the spike, lowering the sputtering yield.