Emission channeling experiments from the decay of to in GaN

Autor:	André Vantomme, Ulrich Wahl, J. G. Correia, B. L. de Vries
Rok vydání:	2003
Předmět:	Photoluminescence Materials science Mechanical Engineering chemistry.chemical_element Electron Condensed Matter Physics Crystallographic defect Root mean square Ion implantation chemistry Mechanics of Materials Excited state General Materials Science Atomic physics Europium Ground state
Zdroj:	Materials Science and Engineering: B. 105:106-110
ISSN:	0921-5107
Popis:	The lattice site location of excited states of 149 Eu was studied by means of the emission channeling technique. The 60 keV implantation of 149 Tb into a GaN thin film was performed at room temperature up to a dose of 2.0×1013 cm−2. This radioactive isotope eventually decays into short-lived excited states of 149 Eu . The conversion electrons emitted in the subsequent decay to the 149 Eu ground state were detected with a position sensitive detector. We measured their angular distributions around the [0 0 0 1], [ 1 1 0 2 ], [ 1 1 0 1 ] and [ 2 1 1 3 ] axes in the as-implanted state and after 600 and 900 °C vacuum annealing. Already in the as-implanted state around 65% of 149∗ Eu atoms were found on substitutional Ga sites. The root mean square (rms) displacements from the substitutional sites in the as-implanted state were found to be around 0.13–0.16 A. Annealing up to 600 °C increased the substitutional fraction by a few percent and slightly reduced the rms displacements, most likely due to the removal of crystal defects in the vicinity of the Eu atoms, resulting in a better incorporation into substitutional sites.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::6d3dd93f75e2368832c1b76aff73b890 https://doi.org/10.1016/j.mseb.2003.08.025 Zobrazit plný text záznamu Full Text from ScienceDirect