Lattice location of Fe in diamond

Incorporation of radioactive Fe-59 atoms in diamond was achieved by implanting precursor Mn-59 isotopes, with an energy of 60 keV and to a dose of 8 x 10(12) cm(-2), into a natural type IIa diamond sample at the online isotope separator ISOLDE at CERN. The lattice sites taken up by the Fe atoms, following 59Mn P-decays, have been investigated using the emission channeling technique. Channeling measurements were made on the electrons emitted in the Fe-59 beta(-) decay. Data were collected with a two-dimensional Si pad detector, along (1 1 0), (1 0 0) and (1 1 1) axial directions from the as-implanted sample and after annealing in vacuum at 600, 900 and 1250 K. The channeling effects showed considerable enhancement with annealing. Fits to the observed patterns with simulations based on the many beam formalism of electron motion through a crystal lattice, show that, after annealing at 1250 K, 65(5)% of the Fe atoms are located at sites with a projected mean displacement less than or equal to 0.2 Angstrom from substitutional sites. (C) 2003 Elsevier Science B.V. All rights reserved.