Articles producció científica> Química Física i Inorgànica

Transparent glass-ceramics with (Eu3+,Yb3+):YNbO4 nanocrystals: Crystallization, structure, optical spectroscopy and cooperative upconversion

  • Dades identificatives

    Identificador: PC:3331
    Autors:
    Mateos, X.Loiko, P.Dymshits, O.Alekseeva, I.Zhilin, A.Tsenter, M.Vilejshikova, E.Bogdanov, KYumashev, K
    Resum:
    . In the present work, we report on a comprehensive study of crystallization, structure and optical spectroscopy of transparent glass-ceramics with (Eu3+,Yb3+):YNbO4 nanocrystals synthesized by a secondary heat-treatment of Li2O–Al2O3–SiO2 glasses doped with rare-earth oxides and nucle-ated by Nb2O5, for the first time, to the best of our knowledge. Heat treatments result in volume crystallization of RENbO4 with the sizes of 4 – 15 nm. Crystals of rare-earth niobates with disor-dered fluorite structure (T’) appear during heat-treatment at 720–740 °C for 6 h, crystals with tetragonal structure (T) appear at higher temperatures or longer durations of heat-treatment, and at >1000 °C the transformation to a monoclinic form (M) begins. Rare-earth niobates act as nu-cleating agents for bulk crystallization of β-quartz solid solutions, the main crystalline phase of the glass-ceramics. Optical spectroscopy confirms entering of both Eu3+ and Yb3+ ions into the RENbO4 nanophase and their specroscopic properties changes according to the T’ → T → M phase transformations. Under UV excitation, glass-ceramics heat-treated at 900 °C provide in-tense red emission with the color coordinates x = 0.665, y = 0.335 (CIE 1931). At 1000 °C, a par-tial reduction of Eu3+ to Eu2+ is observed which allows for tuning of color properties of emission. When excited in the near-IR by an InGaAs diode, the initial glass and glass-ceramics show red cooperative upconversion due to the 2Yb3+ → Eu3+ energy transfer. The efficiency of the latter is ~10%. The developed materials due to the good emission and thermo-mechanical properties are promising for the development of color-tunable red phosphors.
  • Altres:

    Autor segons l'article: Mateos, X. ; Loiko, P. ; Dymshits, O.; Alekseeva, I.; Zhilin, A. ; Tsenter, M. ; Vilejshikova, E. ; Bogdanov, K; Yumashev, K
    Departament: Química Física i Inorgànica
    Autor/s de la URV: MATEOS FERRÉ, XAVIER; Loiko, P. ; Dymshits, O.; Alekseeva, I.; Zhilin, A. ; Tsenter, M. ; Vilejshikova, E. ; Bogdanov, K; Yumashev, K
    Paraules clau: Glass¿ceramics Orthoniobates Europium
    Resum: . In the present work, we report on a comprehensive study of crystallization, structure and optical spectroscopy of transparent glass-ceramics with (Eu3+,Yb3+):YNbO4 nanocrystals synthesized by a secondary heat-treatment of Li2O–Al2O3–SiO2 glasses doped with rare-earth oxides and nucle-ated by Nb2O5, for the first time, to the best of our knowledge. Heat treatments result in volume crystallization of RENbO4 with the sizes of 4 – 15 nm. Crystals of rare-earth niobates with disor-dered fluorite structure (T’) appear during heat-treatment at 720–740 °C for 6 h, crystals with tetragonal structure (T) appear at higher temperatures or longer durations of heat-treatment, and at >1000 °C the transformation to a monoclinic form (M) begins. Rare-earth niobates act as nu-cleating agents for bulk crystallization of β-quartz solid solutions, the main crystalline phase of the glass-ceramics. Optical spectroscopy confirms entering of both Eu3+ and Yb3+ ions into the RENbO4 nanophase and their specroscopic properties changes according to the T’ → T → M phase transformations. Under UV excitation, glass-ceramics heat-treated at 900 °C provide in-tense red emission with the color coordinates x = 0.665, y = 0.335 (CIE 1931). At 1000 °C, a par-tial reduction of Eu3+ to Eu2+ is observed which allows for tuning of color properties of emission. When excited in the near-IR by an InGaAs diode, the initial glass and glass-ceramics show red cooperative upconversion due to the 2Yb3+ → Eu3+ energy transfer. The efficiency of the latter is ~10%. The developed materials due to the good emission and thermo-mechanical properties are promising for the development of color-tunable red phosphors.
    Grup de recerca: Física i Cristal.lografia de Materials
    Àrees temàtiques: Química Química Chemistry
    Accès a la llicència d'ús: https://creativecommons.org/licenses/by/3.0/es/
    ISSN: 0022-2313
    Identificador de l'autor: 0000-0003-1940-1990; ; ; ; ; ; ; ;
    Data d'alta del registre: 2018-09-25
    Pàgina final: 73
    Volum de revista: 179
    Versió de l'article dipositat: info:eu-repo/semantics/submittedVersion
    Enllaç font original: https://www.sciencedirect.com/science/article/abs/pii/S0022231315308632
    URL Document de llicència: https://repositori.urv.cat/ca/proteccio-de-dades/
    DOI de l'article: 10.1016/j.jlumin.2016.06.042
    Entitat: Universitat Rovira i Virgili
    Any de publicació de la revista: 2016
    Pàgina inicial: 64
    Tipus de publicació: Article Artículo Article
  • Paraules clau:

    Iterbi
    Luminiscència
    Glass¿ceramics
    Orthoniobates
    Europium
    Química
    Química
    Chemistry
    0022-2313
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