Incommensurately modulated structure and spectroscopic properties of CaGd2(MoO4)4:Ho3+/Yb3+ phosphors for up-conversion applications

Описание

Тип публикации: статья из журнала

Год издания: 2017

Идентификатор DOI: 10.1016/j.jallcom.2016.06.134

Ключевые слова: Molybdate, Sol-gel synthesis, Modulation, Upconversion, XRD, Raman, RED-EMITTING PHOSPHORS, PHOTOLUMINESCENCE PROPERTIES, LUMINESCENCE PROPERTIES, UPCONVERTING NANOPARTICLES, VIBRATIONAL PROPERTIES, IN-VIVO, TEMPERATURE, BA, CRYSTALS, SR

Аннотация: CaGd2(MoO4)(4):Ho3+/Yb3+ phosphors doped by Ho3+ and Yb3+ (Ho3+ = 0 and 0.05, and Yb3+ = 0, 0.35, 0.40, 0.45 and 0.50) were successfully synthesized by the microwave sol-gel method. The synthesized particles, being formed after heat-treatment at 900 degrees C for 16 h, showed a well crystallized morphology. All compounds are (3 + 2Показать полностью)D incommensurately modulated with superspace group I4(1)/alpha(alpha,beta,0)00(-beta,alpha,0)00. It was found that parameter (alpha(2) + beta(2))(1)/(2) is proportional to cell parameter a for all studied compositions and, therefore, modulation vector k is the same for all known CaRE2(MoO4)(4) compounds. The modulation vector invariance is a specific and valuable feature of this type of the structure. Under the excitation at 980 nm, the doped particles exhibited the yellow emission composed of green (545-nm) and red (655-nm) emission bands due to frequency upconversion (UC). The pump power dependence and CIE chromaticity of the UC emission were evaluated. The shape of UC bands in CaGd2(MoO4)(4):Ho3+/Yb3+ is dependent on the Yb content due to the influence of the crystal field affecting a holmium ion. 13 Raman-active modes of the CaGd2(MoO4)(4) lattice were identified via a comparison of experimental Raman spectra and the lattice dynamics simulation results. Four additional Raman lines were found in the region of stretching vibrations and, at least, two additional modes are present in the bending mode region. These additional modes are ascribed to incommensurate crystal lattice modulation. Luminescence bands of Ho ions are severely broadened due to a statistical disorder in the CaGd2-xYby (MoO4)(4) lattice. (C) 2016 Published by Elsevier B.V.

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Издание

Журнал: Journal of Alloys and Compounds

Выпуск журнала: Vol. 695

Номера страниц: 737-746

ISSN журнала: 09258388

Персоны

  • Lim Chang Sung (Hanseo Univ, Dept Adv Mat Sci & Engn, Seosan 356706, South Korea)
  • Atuchin Victor V. (SB RAS, Inst Semicond Phys, Lab Opt Mat & Struct, Novosibirsk; Tomsk State Univ, Funct Elect Lab, Tomsk 634050, Russia; Novosibirsk State Univ, Lab Semicond & Dielect Mat, Novosibirsk 630090, Russia; Tyumen State Univ, Inst Chem, Tyumen 525003, Russia;; )
  • Aleksandrovsky Aleksandr S. (Siberian Fed Univ, Lab Nonlinear Opt & Spect; SB RAS, Kirensky Inst Phys, Lab Coherent Opt)
  • Molokeev Maxim S. (SB RAS, Kirensky Inst Phys, Lab Crystal Phys; Far Eastern State Transport Univ, Dept Phys, Khabarovsk 680021, Russia;; )
  • Oreshonkov Aleksandr S. (SB RAS, Kirensky Inst Phys, Lab Mol Spect; Siberian Fed Univ, Dept Photon & Laser Technol, Krasnoyarsk 660079, Russia)