Hydrothermal Synthesis, Structure, and Luminescence of Cr3+-Doped Li2SnO3 and Na2SnO3 Stannates

L. Vasylechkoa, V. Sydorchukb, V. Hreba, S. Ubizskiia, S. Khalameidab, A. Luchechkoc, Y. Zhydachevskyya, d aLviv Polytechnic National University, Bandera Str. 12, 79013 Lviv, Ukraine bInstitute for Sorption and Problems of Endoecology, NAS of Ukraine, Henerala Naumova Str. 13, 03164 Kyiv, Uraine cIvan Franko National University of Lviv, Universytetska Str., 1, 79000 Lviv, Ukraine dInstitute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland

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Chromium-doped Li2SnO3 and Na2SnO3 nanocrystalline materials with honeycomb layered monoclinic structure were synthesized by heat treatment of hydrothermally derived precursors at 800 and 900°, respectively. Evolution of phase composition, structural parameters, and average grain size of the Li2SnO3:Cr and Na2SnO3:Cr series versus heat treatment temperature were evaluated by full profile Rietveld refinement. The observed structural behaviour reflects complex processes of rearrangement of stacking faults of honeycomb Li2SnO3:Cr structure during thermal annealing processes. A deep-red emitting Li2SnO3:Cr3+ phosphor was obtained and reported for the first time. The ions of Cr3+ in Li2SnO3 are in the intermediate octahedral crystal field (Dq/B=2.48), which is evident in the photoluminescence occurring at room temperature as broadband stretching from 650 to more than 850 nm (4T2→4A2 transitions) with a residual narrow and sharp emission line at 700 nm (2E →4A2). No photoluminescence of Cr3+ ions was detected at room temperature in as-prepared Na2SnO3:Cr and Li8SnO6:Cr materials.

DOI:10.12693/APhysPolA.141.241 topics: lithium and sodium stannates, hydrothermal synthesis, crystal structure, red luminescence