Fe Emission Mössbauer Study on Gd 3 Ga 5 O 12 implanted with dilute 57 Mn

57Fe emission Mössbauer spectroscopy has been applied to study the lattice location and properties of Fe in gadolinium gallium garnet Gd3Ga5O12 (GGG) single crystals in the temperature interval 300 – 563 K within the extremely dilute (<10−4 at.%) regime following the implantation of 57Mn (T1/2 = 1.5 min.) at ISOLDE/CERN. These results are compared with earlier Mössbauer spectroscopy study of Fe-doped gadolinium gallium This article is part of the Topical Collection on Proceedings of the International Conference on the Applications of the Mössbauer Effect (ICAME 2015), Hamburg, Germany, 13–18 September 2015 H. P. Gunnlaugsson haraldur.p.gunnlaugsson@cern.ch 1 Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee Boulevard, Sofia, 1784, Bulgaria 2 CERN, PH Div, CH-1211 Geneve 23, Switzerland 3 Tokyo University of Science, Tokyo, Japan 4 Physics and Engineering Department, University of Zululand, Zululand, South Africa 5 Department of Physics, K.N. Toosi University of Technology, P.O.Box 15875-4416, Tehran, Iran 6 School of Physics, University of the Witwatersrand, Witwatersrand 2050, South Africa 7 Laboratorio MDM, IMM-CNR, Via Olivetti 2, I-20864 Agrate Brianza (MB), Italy 8 Moscow Institute of Physics and Technology, 9 Institutskiy per., Dolgoprudny, Moscow Region, 141700, Russian Federation 9 BCMaterials & Elektrizitate eta Elektronika Saila, Euskal Herriko Unibertsitatea (UPV/EHU), 48048 Bilbao, Spain 37 Page 2 of 6 Hyperfine Interact (2016) 237:37 garnet Gd3Ga5O12(GGG), with implantation fluences between 8×1015 and 6×1016 atoms cm−2. Three Fe components are observed in the emission Mössbauer 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 daughter 57∗Fe nucleus in the β− decay of 57Mn. In contrast to high fluence 57Fe 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.