The Effect of Nd3+ Composition on Judd-Ofelt Analysis of Lithium Niobate Tellurite Glasses Codoped with Er3+

The modification of absorption characteristics in rare-earth doped tellurite glasses is important in photonics application. The Er3+/Nd3+ doped glasses of the form (69-x)TeO2–15Li2CO3–15Nb2O5–1Er2O3 -(x)Nd2O3 with x =0.2 and 0.6 mol% are successfully made by using conventional melt-quenching technique. The Judd-Ofelt analysis is to determine the local structure and bonding in the vicinity of rare-earth ions. The oscillator strengths are calculated from the absorption spectra and used to evaluate Judd-Ofelt intensity parameters (Ωλ, λ=2, 4 and 6). The values of Ω4 and Ω6 change with the increase of Nd3+ concentration is ascribed to the change in glass network structures. The values of Ω2 are increased from 1.53 to 37.13 (10-22) cm2 with the increase of Nd3+ concentration which indicate an increase in the covalent nature of Nd-O bond and less centrosymmetrical the ion sites. The decrease in τrad for each level with the increase of Nd3+ concentration signifies on how fast a particular level gets depopulated. The values of β for the transitions 4G5/2, 2G7/2 → 4I9/2, 2H11/2 → 4I9/2 and 4F9/2 → 4I9/2 are found to lie in between 99.6 to 100.0%.

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Vibrational, Thermal, and Physical Characterizations of Some Zinc Niobo Tellurite Glasses Doped with Rare Earth (Eu, Dy)-=SUP=-*-=/SUP=-

Оптика и спектроскопия ◽

10.21883/os.2021.04.50785.1012-20 ◽

2021 ◽

Vol 129 (4) ◽

pp. 527

Author(s):

Afrash Ejigu A ◽

K.P. Ramesh ◽

Gajanan Honnavar

Keyword(s):

Rare Earth ◽

Packing Density ◽

Local Environment ◽

Peak Shift ◽

Rare Earth Ions ◽

Physical Parameters ◽

Tellurite Glasses ◽

Rare Earth Ion ◽

Raman Spectroscopic ◽

Doped Glasses

In this communication, we report physical and thermal properties along with Raman spectroscopic investigations on Zinc Niobo Tellurite glass systems doped with Eu2O3 and Dy2O3 at the expense of TeO2. The glasses have been synthesized by the melt quenching technique. Physical parameters like density, molar volume, packing density were estimated. The density of the un-doped glasses increases with increasing mol% of the modifier (ZnO) whereas the glass transition temperature (Tg) decreases. We have observed an increase in the density of the base glass systems which are doped with rare earth (RE) dopants. The packing density of the un-doped glasses remains almost constant with increasing modifier content suggesting that there is not much change in the local environment. Raman spectra were recorded at room temperature and assigned to TeO4 and TeO3 structural units in these glasses. The peak shift, full width at half maximum (FWHM) of the de-convoluted Raman peaks were analyzed to get information about the local environment. It is observed that these compositions of tellurite glasses are good host materials for rare earth ions as they offer voids in the network. Further, it was observed that the rare earth ion doping has not affected the local environment of the glasses; Dy3+ ions have a slightly higher tendency to polarize Te-O bonds than the Eu3+ ions. Keywords: Niobium-based tellurite glasses, XRD, DSC, FTIR.

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On the influence of low silica content on phosphates glasses doped with Erbium Ions

QUARKS: Brazilian Electronic Journal of Physics, Chemistry and Materials Science ◽

10.34019/2674-9688.2020.v3.30205 ◽

2020 ◽

Vol 3 (1) ◽

Author(s):

Diogo Rúbio Sant'Anna das Dores ◽

Victor Rocha da Silva ◽

Geraldo Henriques Silva ◽

Victor Hugo De Oliveira ◽

Zélia Maria da Costa Ludwig ◽

...

Keyword(s):

Rare Earth ◽

Silicon Oxide ◽

Glass Network ◽

Spectroscopic Characterization ◽

Radiative Transition ◽

Infrared Emission ◽

Silica Content ◽

Rare Earth Ions ◽

Oscillator Strengths ◽

Erbium Ions

This work describes the spectroscopic characterization of a phosphate glass matrix doped with different Erbium concentrations. In order to increase the resistance of the glass, 3 mol %, of silicon oxide were added to the phosphate matrix. A study of the optical absorption, luminescence and lifetime was conducted in order to characterize the infrared emission of Er3+ ions at 1540 nm, due to the radiative transition 4I13/2 →4I15/2. Judd-Ofelt spectral analysis was carried out to determine the local structure and bonding in the vicinity of rare-earth ions. The experimental oscillator strengths calculated from the absorption spectra were used to evaluate the Judd-Ofelt intensity parameters Ωλ (λ = 2, 4 and 6). Changes in the glass density, refractive index and the values of Ω4 and Ω6 with different rare-earth concentrations are ascribed to changes in the glass network structure. Our results indicate that the present glass is a quite good matrix for Erbium ions, and the quantum efficiency of the 1540 nm emission was high. No quenching mechanisms were detected up to 2% of Erbium concentration.

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