Photoluminescence and electron-vibrational interaction in 4f^n?15d states of Ce³⁺ or Pr³⁺ ions doped LnBO₃ (Ln=Lu, Y, La) orthoborates materials

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• 作者：L. Guerbous^a ; ^{guerbous@yahoo.fr} ; M. Seraiche^a ; ^b ; O. Krachni^c
• 关键词：Ce3+ ; Pr3+ ; 4fn&rarr ; 4fn&minus ; 15d transitions ; Orthoborates ; UV luminescence ; Electron-vibrational interaction
• 刊名：Journal of Luminescence
• 出版年：2013
• 出版时间：February, 2013
• 年：2013
• 卷：134
• 期：Complete
• 页码：165-173
• 全文大小：1517 K

文摘

Calcite, vaterite and aragonite type rare earth LnBO₃ (Ln=Lu, Y, La) orthoborate powders, doped with 1 % cerium or praseodymium, were prepared by the classical solid state reaction method. The structure and the morphology of these powder materials were checked by X-ray Diffraction, Fourier Transform Infra Red Spectroscopy (FTIR) and Scanning Electron Microscopy. Room temperature excitation and emission spectra of four compounds: LuBO₃ with calcite and vaterite structure, YBO₃ (vaterite type structure) and LaBO₃ with aragonite, doped with 1 % cerium or praseodymium ions, have been measured and investigated. The effect of Ce³⁺ and Pr³⁺ crystalline environment in these compounds on the position of their 5d (4f5d) levels has been discussed. This work is also devoted to the problem of the electron-vibrational interaction (EVI) in 4f-5d optical transitions in orthoborate materials. The emission and excitation 4f-5d transitions resulted in broad vibronic bands whose shape functions were described and found. The main EVI parameters, such as the Huang-Rhys factor, effective phonon energy, and zero-phonon line position, were estimated. These values are checked by modeling the Ce³⁺ 5d-4f and Pr³⁺ 4f5d-4f² emission lines shapes, in which good agreement with experimental spectra confirms validity of the performed analysis.