%0 Journal Article %T PAL spectroscopy of rare-earth doped Ga-Ge-Te/Se glasses %+ Institut des Sciences Chimiques de Rennes (ISCR) %+ Rzeszow University of Technology %+ Opole University of Technology %+ Jan Dlugosz University in Czestochowa %A Shpotyuk, Ya. %A Ingram, A. %A Shpotyuk, O %Z ShYa acknowledges support for this research funded by Marie-Curie ActionFP7-PEOPLE-2010-ITN under the GlaCERCo project. %< avec comité de lecture %@ 0022-3697 %J Journal of Physics and Chemistry of Solids %I Elsevier %V 91 %P 76-79 %8 2016 %D 2016 %R 10.1016/j.jpcs.2015.12.010 %K chalcogenides %K Defects %K Glasses %K Microstructure %K positron annihilation spectroscopy %Z Chemical SciencesJournal articles %X Positron annihilation lifetime (PAL) spectroscopy was applied for the first time to study free-volume void evolution in chalcogenide glasses of Ga-Ge-Te/Se cut-section exemplified by glassy Ga10Ge15Te75 and Ga10Ge15Te72Se3 doped with 500 ppm of Tb3+ or Pr3+. The collected PAL spectra reconstructed within two-state trapping model reveal decaying tendency in positron trapping efficiency in these glasses under rare-earth doping. This effect results in unchanged or slightly increased defect-related lifetimes τ2 at the cost of more strong decrease in I2 intensities, as well as reduced positron trapping rate in defects and fraction of trapped positrons. Observed changes are ascribed to rare-earth activated elimination of intrinsic free volumes associated mainly with negatively-charged states of chalcogen atoms especially those neighboring with Ga-based polyhedrons. %G English %2 https://univ-rennes.hal.science/hal-01254798/document %2 https://univ-rennes.hal.science/hal-01254798/file/PAL%20spectroscopy%20of%20rare-earth_accepted.pdf %L hal-01254798 %U https://univ-rennes.hal.science/hal-01254798 %~ UNIV-RENNES1 %~ CNRS %~ INSA-RENNES %~ ENSC-RENNES %~ ISCR %~ STATS-UR1 %~ UR1-SPM %~ INC-CNRS %~ UR1-UFR-SPM %~ UR1-HAL %~ UR1-SDLM %~ TEST-UNIV-RENNES %~ TEST-UR-CSS %~ UNIV-RENNES %~ INSA-GROUPE %~ UR1-MMS %~ TEST2-HALCNRS