Secondary emission of neutral and charged particles from intermetallic single-crystal

Sputtering, secondary ion and secondary electron emission were studied experimentally for an intermetallic Ni4Mo compound with high corrosion resistance and great hardness, which is used as material for constructing components of rockets and nuclear reactors. The process of sputtering was analyzed by molecular dynamics simulations of Ni4Mo (111) face for unchanged and changed composition (with segregation) of topmost layers of a disordered and ordered crystal. Predominant exit of Ni and Mo atoms in close-packed directions was observed and explained by correlated collisions. Both nickel and molybdenum atoms are ejected in the same crystallographic directions for a disordered crystal. For an ordered crystal the nickel atoms deviate from these directions. The origin of sputtering and number of ejected particles generated has been calculated. For secondary electron emission from the (111) Ni4Mo face the maxima in close-packed directions were obtained experimentally and explained by scattering of primary and secondary electrons on atoms located in the lateral sides of open channels.