Implantation site of rare earths in single-crystalline ZnO

The lattice location of rare-earth Er-167m in single-crystalline hexagonal ZnO was studied by means of the emission channeling technique. Following 60-keV, room-temperature implantation of the precursor isotope Tm-167 at doses of 1.3-2.8x10(13) cm(-2) and annealing up to 900 degreesC, the angular distribution of conversion electrons emitted by the radioactive isotope Er-167m was measured by a position-sensitive electron detector. The conversion electron emission patterns from Er-167m around the [0001], [(1) under bar 102], [(1) under bar 101], and [(2) under bar 113] directions give direct evidence that the large majority of Er atoms (75%-90%) occupies substitutional Zn sites. (C) 2003 American Institute of Physics.