Recoil implantation after nuclear reactions for the investigation of nuclear quadrupole interactions

With the aid of atomic probes produced by nuclear reactions in an accelerator, electric nuclear quadrupole interactions can be studied systematically in a nearly freely selectable environment. When these probes are produced in a thin reaction layer (approximately 1,000 A), even low-energy nuclear reactions may be used for implantation in a matrix lying behind it. The number of measurable interactions, whose strength depends on the quadrupole moment of the probe and on the electric field gradient of the matrix, is thus considerably increased. The implantation of to probes into polyvalent, non-cubic metals is used as an example: The nucleus 67Ge was studied in the matrices Ga, Cd, In, Sn and Sb, and the nucleus 67Zn in Cd. The measured interactions show impurity spectres which suggest a polycrystalline structure of the evaporated metal layers and a substitutional site of the probes. (orig./WL)