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Type: 
Journal
Description: 
57Fe emission Mossbauer spectroscopy has been applied to study the lattice location and properties of Fe in gadolinium gallium garnet Gd3Ga5 O 12 (GGG) single crystals in the temperature interval 300–563 K within the extremely dilute (< 10− 4 at.%) regime following the implantation of57Mn (T 1/2= 1.5 min.) at ISOLDE/CERN. These results are compared with earlier Mossbauer spectroscopy study of Fe-doped gadolinium gallium garnet Gd3Ga5 O 12 (GGG), with implantation fluences between 8× 1015 and 6× 1016 atoms cm− 2. Three Fe components are observed in the emission Mossbauer spectra:(i) high spin Fe2+ located at damage sites due to the implantation process,(ii) high spin Fe3+ at substitutional tetrahedral Ga sites, and (iii) interstitial Fe, probably due to the recoil imparted on the daughter57∗ Fe nucleus in the β− decay of57Mn. In contrast to high fluence57Fe implantation studies the Fe3+ ions are found to prefer the tetrahedral Ga site over the octahedral Ga site. No annealing stages are evident in the temperature range investigated. Despite the very low concentration, high-spin Fe3+ shows fast spin relaxation, presumably due to an indirect interaction between nearby gadolinium atoms.
Publisher: 
Springer Science and Business Media LLC
Publication date: 
22 Feb 2016
Authors: 

Karl Johnston, HP Gislason, Hilary Masenda, AM Gerami, Deena Naidoo, Krish Bharuth-Ram, I Unzueta, TE Mølholt, V Adoons, Guido Langouche, M Ncube, Roberto Mantovan, Kiyoshi Nomura, YA Matveyev, PB Krastev, Haraldur P Gunnlaugsson, Sveinn Olafsson

Biblio References: 
Volume: 237
Origin: 
Hyperfine Interactions