Thermal behaviour of the NaYF4:Yb3+,R3+ materials

  • Tero Laihinen
  • Mika Lastusaari
  • Laura Pihlgren
  • Lucas C. V. Rodrigues
  • Jorma Hölsä


The NaYF4:Yb3+,R3+ (R: none, Pr, Nd, Sm, Eu, Tb or Dy) materials were prepared with selected dopant concentrations, using co-precipitation synthesis, to study the effect of the dopant and its concentration on the structure of these materials. The thermal behaviour of the as-prepared materials was studied with differential scanning calorimetry (DSC) and thermogravimetry. The structures prior to and after annealing were identified with X-ray powder diffraction. The materials were mainly hexagonal with occasional slight cubic impurity. The DSC curves revealed the cubic-to-hexagonal phase transition at 400–450 °C which temperature changes irregularly with the R3+ dopant and its concentration. The specific enthalpy of this transition varies also in a complicated way but may be correlated with the completeness of the transition. The hexagonal-to-cubic transition temperature (ca. 670 °C) is rather constant regardless of the R3+ dopant or its concentration. The temperatures and specific enthalpies of the phase transitions are useful when choosing the optimum dopant concentrations. It is also possible to estimate the structure prior to annealing with significant savings in use of resources. Only with Sm3+ and Dy3+ doping, no visible up-conversion luminescence was observed—in addition to the Er3+ and Tm3+ impurity emission. Eventually, it was found that the hexagonal form gives much stronger up-conversion luminescence and changes in the rare earth concentration allows the formation of this form.


NaRF4 R3+ doping Phase transitions DSC TG 


  1. 1.
    Auzel F. Upconversion and anti-stokes processes with f and d ions in solids. Chem Rev. 2004;104:139–73.CrossRefGoogle Scholar
  2. 2.
    Antal T, Harju E, Pihlgren L, Lastusaari M, Tyystjärvi T, Hölsä J, Tyystjärvi E. Use of near-infrared radiation for oxygenic photosynthesis via photon up-conversion. Int J Hydrogen Energy. 2012;37:8859–63.CrossRefGoogle Scholar
  3. 3.
    de Wild J, Meijerink A, Rath JK, van Stark WGJHM, Schropp REI. Upconverter solar cells: materials and applications. Energy Environ Sci. 2011;4:4835–48.CrossRefGoogle Scholar
  4. 4.
    Ylihärsilä M, Valta T, Karp M, Hattara L, Harju E, Hölsä J, Saviranta P, Waris M, Soukka T. Oligonucleotide array-in-well platform for detection and genotyping human adenoviruses by utilizing upconverting phosphor label technology. Anal Chem. 2011;83:1456–61.CrossRefGoogle Scholar
  5. 5.
    Krämer KW, Biner D, Frei G, Güdel HU, Hehlen M, Lüthi S. Hexagonal sodium yttrium fluoride based green and blue emitting upconversion phosphors. Chem Mater. 2004;16:1244–51.CrossRefGoogle Scholar
  6. 6.
    Zhao J, Sun Y, Kong X, Tian L, Wang Y, Tu L, Zhao J, Zhang H. Controlled synthesis, formation mechanism, and great enhancement of red upconversion luminescence of NaYF4:Yb3+,Er3+ nanocrystals/submicroplates at low doping level. J Phys Chem B. 2008;112:15666–72.CrossRefGoogle Scholar
  7. 7.
    Hyppänen I, Hölsä J, Kankare J, Lastusaari M, Pihlgren L, Soukka T. Preparation and up-conversion luminescence properties of NaYF4:Yb3+,Er3+ nanomaterials. Terrae Rarae. 2009;16:1–6.Google Scholar
  8. 8.
    Harju E, Hyppänen I, Hölsä J, Kankare J, Lahtinen M, Lastusaari M, Pihlgren L, Soukka T. Polymorphism of NaYF4:Yb3+,Er3+ up-conversion luminescence materials. Z Kristallogr Proc. 2011;1:381–7.Google Scholar
  9. 9.
    Thoma RE, Insley H, Hebert GM. Sodium fluoride–lanthanide trifluoride systems. Inorg Chem. 1966;5:1222–9.Google Scholar
  10. 10.
    PCPDFWIN v. 1.30, Powder Diffraction File, 1997, International Centre for Diffraction Data, entries 06-0342 (cubic NaYF4) and 28-1192 (hexagonal Na(Y0.57Yb0.39Er0.04)F4).Google Scholar
  11. 11.
    Mathews MD, Ambekar BR, Tyagi AK, Köhler J. J Alloys Compd. 2004;377:162–6.Google Scholar
  12. 12.
    Malinowski M, Joubert M-F, Jacquier B. Infrared to blue up-conversion in Pr3+ doped YAG and LiYF crystals. J Lumin. 1994;60–61:179–82.CrossRefGoogle Scholar
  13. 13.
    Pollnau M, Hardman PJ, Clarkson WA, Hanna DC. Upconversion, lifetime quenching, and ground-state bleaching in Nd3+:LiYF4. Opt Commun. 1998;147:203–11.Google Scholar
  14. 14.
    Zhou Y, Lin J, Wang S. Energy transfer and upconversion luminescence properties of Y2O3:Sm and Gd2O3:Sm phosphors. J Solid State Chem. 2003;171:391–5.Google Scholar
  15. 15.
    Stręk W, Dereń PJ, Bednarkiewicz A, Kalisky Y, Boulanger P. Efficient up-conversion in KYb0.8Eu0.2(WO4)2 crystal. J Alloys Compd. 2000;300–301:180–3.CrossRefGoogle Scholar
  16. 16.
    Stręk W, Bednarkiewicz A, Dereń PJ. Power dependence of luminescence of Tb3+-doped KYb(WO4)2 crystal. J Lumin. 2001;92:229–35.CrossRefGoogle Scholar
  17. 17.
    Wermuth M, Riedener T, Güdel HU. Spectroscopy and upconversion mechanisms of CsCdBr3:Dy3+. Phys Rev B. 1998;57:4369–76.CrossRefGoogle Scholar
  18. 18.
    Müller P, Wermuth M, Güdel HU. Mechanisms of near-infrared to visible upconversion in CsCdBr3:Ho3+. Chem Phys Lett. 1998;290:105–11.CrossRefGoogle Scholar
  19. 19.
    Yi G, Lu H, Zhao S, Ge Y, Yang W, Chen D, Guo LH. Synthesis, characterization, and biological application of size-controlled nanocrystalline NaYF4:Yb,Er infrared-to-visible up-conversion phosphors. Nano Lett. 2004;4:2191–6.CrossRefGoogle Scholar
  20. 20.
    Heer S, Kömpe K, Güdel HU, Haase M. Highly efficient multicolour upconversion emission in transparent colloids of lanthanide doped NaYF4 nanocrystals. Adv Mater. 2004;16:2102–5.CrossRefGoogle Scholar
  21. 21.
    Hölsä J, Laihinen T, Laamanen T, Lastusaari M, Pihlgren L, Rodrigues LCV, Soukka T. Enhancement of the up-conversion luminescence from NaYF4:Yb3+,Tb3+. Phys B. 2014;439:20–3.Google Scholar
  22. 22.
    Geusic JE, Marcos HM, Van Uitert LG. Laser oscillations in Nd-doped yttrium aluminum, yttrium gallium and gadolinium garnets. Appl Phys Lett. 1964;4:182–4.CrossRefGoogle Scholar
  23. 23.
    Kaczmarek SM, Leniec G, Typek J, Boulon G, Bensalah A. Optical and EPR study of BaY2F8 single crystals doped with Yb. J Lumin. 2009;129:1568–74.Google Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2015

Authors and Affiliations

  • Tero Laihinen
    • 1
    • 2
  • Mika Lastusaari
    • 1
    • 3
  • Laura Pihlgren
    • 1
    • 2
  • Lucas C. V. Rodrigues
    • 1
    • 4
  • Jorma Hölsä
    • 1
    • 3
    • 4
  1. 1.Department of ChemistryUniversity of TurkuTurkuFinland
  2. 2.Doctoral Programme in Physical and Chemical SciencesUniversity of Turku Graduate School (UTUGS)TurkuFinland
  3. 3.Turku University Centre for Materials and Surfaces (MatSurf)TurkuFinland
  4. 4.Instituto de QuímicaUniversidade de São PauloSão Paulo-SPBrazil

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