Implantation site of rare earths in single-crystalline ZnO

The lattice location of rare-earth Er167m in single-crystalline hexagonal ZnO was studied by means of the emission channeling technique. Following 60-keV, room-temperature implantation of the precursor isotope Tm167 at doses of 1.3–2.8×1013 cm−2 and annealing up to 900 °C, the angular distribution of conversion electrons emitted by the radioactive isotope Er167m was measured by a position-sensitive electron detector. The conversion electron emission patterns from Er167m around the [0001], [1_102], [1_101], and [2_113] directions give direct evidence that the large majority of Er atoms (75%–90%) occupies substitutional Zn sites.