Wydział Chemii

Kamil Korzeniowski

Marcin Sobczyk

2018

Journal of Alloys and Compounds

753

717-724

10.1016/j.jallcom.2018.04.162

Naukowa

Angielski

Artykuł

The Y_1-xSm_xTaO₄ (x = 0.1, 0.5, 1.0, 2.0 and 5.0) compounds have been synthesized by conventional solid state method using disodium tetraborate as flux. The growth process of title compounds was studied using X-ray diffraction and electron microscopy (SEM and TEM). The powder diffraction pattern was indexed on a monoclinic cell, space group P2/a, lattice parameters: a = 5.302, b = 5.454 and c = 5.115 Å, Z = 2 and V = 146.97 ų. The absorption (300 K) and fluorescence spectra (5 and 300 K) as well as the fluorescence dynamics of the Sm³⁺:YTaO₄ are presented and analysed in detail. The room-temperature absorption spectra have been analysed using the Judd-Ofelt approach. The intensity parameters have been evaluated and subsequently used to calculate fundamental spectroscopic parameters: the spontaneous transition probabilities, the branching ration, emission cross-sections and natural lifetime for the ⁴G(4)_5/2 emitting level. The luminescencespectra recorded between 5 and 300 K are composed of transitions from the ⁴G(4)_5/2 level to the ⁶H_5/2, ⁶H_7/2, ⁶H_9/2, ⁶H_11/2, ⁶H_13/2, ⁶H_15/2⁶F_1/2, ⁶F_3/2 and ⁶F_5/2 levels. The maximum emission cross-section has been calculated to be 0.935 and 0.985 × 10⁻²¹ cm² at 609.1 and 657.1 nm, respectively. The electron–phonon coupling parameter α¯ was found to be in the range 127–512 cm⁻¹ for the ⁴G(4)_5/2 → ⁶H_5/2, ⁴G(4)_5/2 → ⁶H_7/2 and ⁴G(4)_5/2 → ⁶H_9/2transitions.

Judd-Ofelt analysis, luminescence properties, Electron-phonon coupling, Cross-relaxation, Sm3+, YTaO4

https://doi.org/10.1016/j.jallcom.2018.04.162

http://www.elsevier.com