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Keywords:

Science & Technology, Physical Sciences, Physics, Atomic, Molecular & Chemical, Physics, Condensed Matter, Physics, Nuclear, Physics, Gadolinium gallium garnet (Gd3Ga5O12), Mn-57 implantation, Mossbauer emission spectroscopy, Fe sites, IRON, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, 0204 Condensed Matter Physics, General Physics, 5102 Atomic, molecular and optical physics, 5104 Condensed matter physics, 5106 Nuclear and plasma physics

Abstract:

© 2016, Springer International Publishing Switzerland. 57 Fe emission Mössbauer spectroscopy has been applied to study the lattice location and properties of Fe in gadolinium gallium garnet Gd 3 Ga 5 O 12 (GGG) single crystals in the temperature interval 300 – 563 K within the extremely dilute (<10 −4 at.%) regime following the implantation of 57 Mn (T 1/2 = 1.5 min.) at ISOLDE/CERN. These results are compared with earlier Mössbauer spectroscopy study of Fe-doped gadolinium gallium garnet Gd 3 Ga 5 O 12 (GGG), with implantation fluences between 8×10 15 and 6×10 16 atoms cm −2 . Three Fe components are observed in the emission Mössbauer spectra: (i) high spin Fe 2+ located at damage sites due to the implantation process, (ii) high spin Fe 3+ at substitutional tetrahedral Ga sites, and (iii) interstitial Fe, probably due to the recoil imparted on the daughter 57∗ Fe nucleus in the β − decay of 57 Mn. In contrast to high fluence 57 Fe implantation studies the Fe 3+ 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 Fe 3+ shows fast spin relaxation, presumably due to an indirect interaction between nearby gadolinium atoms.