Investigation of Co Ions Diffusion in Gd3Ga5O12 Single Crystals

D. Sugaka,b, I.I. Syvorotkaa,b, U. Yakhnevych a, O. Buryy a, M. Vakiva,b, S. Ubizskii a, D. Włodarczyk c, Ya. Zhydachevskyya,c, A. Pieniążek c, R. Jakiela c and A. Suchockic,d aLviv Polytechnic National University, Lviv, Ukraine bScientific Research Company "Electron-Carat", Lviv, Ukraine cInstitute of Physics, Polish Academy of Sciences, Warsaw, Poland dInstitute of Physics, Kazimierz Wielki University, Bydgoszcz, Poland

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Spatial changes of properties of Gd3Ga5O12 (GGG) single crystals caused by diffusion of cobalt ions during high-temperature annealing (1200°C, 24 h) in Co3O4 powder are investigated. The registration of these changes was carried out by optical spectrophotometry, microscopy and micro-Raman scattering methods. Changes in structure of near-surface layers of the crystal were investigated by X-ray diffraction technique. It was shown that the additional absorption induced by annealing is related to intra-center optical transitions in Co2+ ions, which occupy tetrahedral positions in the garnet structure at the distances of 250-500 μm from the crystal surface. The dependence of induced absorption with depth has got a non-monotonous character with a maximum at 400 μm. A comparison of the results obtained by different methods allows to suppose that the thermal treatment of GGG in the presence of cobalt ions leads to formation of the structurally and chemically non-uniform: layer with a width about 500 μm.

DOI: 10.12693/APhysPolA.133.933 PACS numbers: 66.30.-h, 78.20.-e