scholarly journals Potential Glass Network for IR Applications and Rare-Earth Ions

2021 ◽  
Vol 140 (3) ◽  
pp. 222-227
Author(s):  
İ. Kabalci ◽  
H. Gökçe ◽  
N.Ö Körpe
Keyword(s):  
Rare Earth ◽  
Glass Network ◽  
Rare Earth Ions

Characterization of Aluminophosphate Glasses Containing Pr3+, Er3+, Gd3+ and Yb3+ Ions

2008 ◽  
Vol 39-40 ◽  
pp. 61-64 ◽  
Author(s):  
M. Elisa ◽  
Ileana Cristina Vasiliu ◽  
Cristiana Eugenia Ana Grigorescu ◽  
B. Grigoras ◽  
H. Niciu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Absorption Spectra ◽  
Glass Network ◽  
Phosphate Glasses ◽  
Rare Earth Ions ◽  
Electronic Transitions ◽  
Ir Absorption ◽  
Optical Phonons ◽  
Infra Red ◽  
Aluminophosphate Glasses

A wet non-conventional method for preparing aluminophosphate glasses is presented. Aluminophosphate glasses belonging to the oxide system Li2O-BaO-Al2O3-La2O3-P2O5, doped with rare-earth ions (Pr3+, Er3+, Gd3+, and Yb3+) were obtained. The influence of the doping ions on the optical properties of the phosphate glasses has been investigated in relation with micro-structural and local electronic phenomena The optical behavior of Li2O-BaO-Al2O3-La2O3-P2O5 glasses doped with 3% mol. rare-earth ions has been studied by ultra-violet-visible-near-infra-red (UV-VISNIR) spectroscopy. The transmission spectra revealed electronic transitions between 4f and 6s inner orbital of the rare-earth ions. Structural information via optical phonons was provided by infra-red (IR) absorption spectra in the range 400-4000 cm-1. IR optical phonons are characteristic for the vitreous phosphate network, showing out the glass network-forming role of P2O5. The absorption spectra present the main PO2 and P-O-P symmetrical stretch modes besides P-O-P bend mode, P-OH, P=O, PO3 2-, asymmetrical and symmetrical vibration modes. Fluorescence spectra of the rareearth- doped aluminophosphate glasses, in the visible range, were obtained by laser excitation at 514.5 nm. The fluorescence signals revealed specific electronic transitions, which provide visible and near-infra-red emission. Glasses containing rare-earth ions exhibit luminescence at the following wavelengths: Pr3+ ions at 820 nm and 880 nm, Er3+ ions at 520 nm, 550 nm and 560 nm, Gd3+ ions at 530 nm, 540 nm, 550 nm 820 and 880 nm, Yb3+ions at 530 nm, 540 nm, 550 nm and 980 nm.

Local symmetry and Z-scan analysis of ZnSe/Eu3+ doped sol–gel silica hosts

2010 ◽  
Vol 88 (7) ◽  
pp. 493-500 ◽  
Author(s):  
Siby Mathew ◽  
K. V. Arun Kumar ◽  
C. Sudarsanakumar ◽  
V. P.N. Nampoori ◽  
N. V. Unnikrishnan
Keyword(s):  
Rare Earth ◽  
Sol Gel ◽  
Glass Network ◽  
Local Symmetry ◽  
Wide Distribution ◽  
Rare Earth Ions ◽  
Saturable Absorption ◽  
Rare Earth Ion ◽  
Enhanced Absorption ◽  
The Rare Earth

Vibrational state side-band spectral analysis of silica matrices, doped with ZnSe/Eu3+ ions, associated with the excitation transition 7F0→5D2 is used to analyze the local asymmetry of the rare earth ions in the glass host. The large inhomogeneous linewidth for the ZnSe co-doped samples indicates the wide distribution of the Eu3+ ions in the matrix and is related to the flexibility of the local glass network. The fluorescence spectra reveal that the intensity of the characteristic emission of europium increases considerably in the presence of ZnSe particles. This phenomenon can be explained by the energy transfer resulting from electron–hole recombination in the ZnSe to the rare earth ion. Nonlinear optical absorption of the sample is also investigated at a wavelength of 532 nm, using open aperture Z-scan technique. The sample exhibits reversible saturable absorption (RSA), which is found to depend on excitation fluence. RSA is due to the enhanced absorption resulting from the electron dynamics in nano-crystallites.

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

2017 ◽  
Vol 268 ◽  
pp. 191-197 ◽  
Author(s):  
Nurhafizah Hasim ◽  
Md Supar Rohani
Keyword(s):  
Rare Earth ◽  
Glass Network ◽  
Rare Earth Ions ◽  
Oscillator Strengths ◽  
Tellurite Glasses ◽  
Melt Quenching ◽  
Intensity Parameters ◽  
Doped Glasses ◽  
Rare Earth Doped ◽  
Covalent Nature

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%.

scholarly journals Modified absorption attributes of neodymium doped magnesium-zinc-sulfophosphate glass

2017 ◽  
Vol 13 (3) ◽  
Author(s):  
Nur Nabihah Yusof ◽  
Sib Krishna Ghoshal ◽  
Muhammad Firdaus Omar
Keyword(s):  
Rare Earth ◽  
Glass Network ◽  
Xrd Analysis ◽  
Photonic Devices ◽  
Rare Earth Ions ◽  
Glass System ◽  
Ion Concentration ◽  
Subsequent Transformation ◽  
Physical Density ◽  
Doped Glass

Rare-earth doped glass systems with improved absorption and emission features are greatly demanding for diverse applications. In this endavour, selection of right glass host, modifier, rare earth ions with optimized composition is the key issue. This communication reports the conventional melt-quench synthesis of neodymium (Nd3+) doped magnesium-zinc- sulfophosphate glass system of the form (60-x)P2O5-20MgO-20ZnSO4-xNd2O3 (x = 0, 0.5, 1, 1.5, 2.0 and 2.5 mol%). The influence of varying Nd3+ contents on the physical (density, molar volume, molar refractivity, refractive index and electronic polarizability) and absorption properties of the prepared glass system is determined. The amorphousity of the obtained samples is confirmed by XRD analysis. The glass refractive indices (ranged from 1.85 to 1.90)  and densites (between 2.63 to 2.77 g.cm-3) are found to increase with increasing concentration of Nd3+ ion. Furthermore, the energies associated with the direct and indirect optical transitions across the forbidden gap are observed to reduce with the increase of Nd3+ ion concentration. Meanwhile, the increase of Urbach energy with increasing Nd3+doping is ascribed to the interaction of rare earth ions with the ligands of the glass network and subsequent transformation of weak bonds into defects. The room temperature UV–Vis-NIR spectra revealed eleven absorption band corresponding to the transitions from the ground state to various excited states of the Nd3+ ion. Incorporation of  Nd3+ ion is discerned to enhance the glass absorbance appreciably together with the alteration of physical properties. Present findings may be beneficial for the advancement of Nd3+ ions doped magnesium-zinc-sulfophosphate glass system based photonic devices especially for infrared solid state laser.

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

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.

Characterization of Rare-Earth Fluoride Anti-Stokes Phosphors by Scanning arid Transmission Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 142-143
Author(s):  
N. M. P. Low ◽  
L. E. Brosselard
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Elevated Temperatures ◽  
Stoichiometric Composition ◽  
Rare Earth Ions ◽  
Crystalline Solid ◽  
Precipitation Process ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Rare Earth Fluorides

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.

Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Saturation Magnetization ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Rare Earth Ions ◽  
Ion Concentration ◽  
Zn Ferrite ◽  
Auto Combustion ◽  
Combustion Technique

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.

scholarly journals Structure, Luminescence, and Magnetic Properties of Crystalline Manganese Tungstate Doped with Rare Earth Ion

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3717
Author(s):  
Jae-Young Jung ◽  
Soung-Soo Yi ◽  
Dong-Hyun Hwang ◽  
Chang-Sik Son
Keyword(s):  
Magnetic Field ◽  
Rare Earth ◽  
Sintering Temperature ◽  
Luminescent Properties ◽  
Concentration Quenching ◽  
Rare Earth Ions ◽  
Precipitation Method ◽  
Rare Earth Ion ◽  
Co Precipitation ◽  
Quenching Phenomenon

The precursor prepared by co-precipitation method was sintered at various temperatures to synthesize crystalline manganese tungstate (MnWO4). Sintered MnWO4 showed the best crystallinity at a sintering temperature of 800 °C. Rare earth ion (Dysprosium; Dy3+) was added when preparing the precursor to enhance the magnetic and luminescent properties of crystalline MnWO4 based on these sintering temperature conditions. As the amount of rare earth ions was changed, the magnetic and luminescent characteristics were enhanced; however, after 0.1 mol.%, the luminescent characteristics decreased due to the concentration quenching phenomenon. In addition, a composite was prepared by mixing MnWO4 powder, with enhanced magnetism and luminescence properties due to the addition of dysprosium, with epoxy. To one of the two prepared composites a magnetic field was applied to induce alignment of the MnWO4 particles. Aligned particles showed stronger luminescence than the composite sample prepared with unsorted particles. As a result of this, it was suggested that it can be used as phosphor and a photosensitizer by utilizing the magnetic and luminescent properties of the synthesized MnWO4 powder with the addition of rare earth ions.

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