Detection of low−mass impurities in thin films using MeV heavy−ion elastic scattering and coincidence detection techniques

The usefulness of heavy−ion forward scattering coincidence measurements is demonstrated for the detection of low−mass impurity atoms in thin self−supporting nickel and gold films. Oxygen beams of 15−20 MeV have been used to detect 16O and 24Mg atoms in nickel films ?200 μg cm−2 thick and chlorine beams of 40 MeV to detect 39K and 63Cu atoms in gold films ?350 μg cm−2 thick. The detection sensitivity and mass discrimination are functions of the angle of acceptance of the detectors. Impurity atom concentrations of the order 1014 atoms cm−2 are detectable. Depth information is available from the energy spectra. Possible application of the detection technique to the determination of the lattice site of low−mass impurities, by channeling in thin single crystals, is considered.

Detection of low−mass impurities in thin films using MeV heavy−ion elastic scattering and coincidence detection techniques Journal Articles