ATOMIC DISPLACEMENT PROCESS IN GOLD

Experimental and theoretical results are presented which bear on the directional dependence of threshold displacement energy Td(θ′;,φ′;). The major experimental results is that the energy dependence of the electron damage rates measured in thin single crystals oriented along the three low-index directions is nearly the same. With the assumption that Td(110) and Td(100) correspond to local minima, the data indicate that Td(100)∼Td(110)∼36 eV. A corresponding theoretical value of Td(100)=36±2 eV is found when a Born-Mayer-type potential with parameters derived by Andersen and Sigmund is used in computer calculations. Evidence is presented to show that experimentally derived threshold energies may not reflect true Td values if they correspond to a local maximum in the threshold energy surface, as may be the case in the 111 direction. © 1969 The American Physical Society.