Effect of heat treatment on the absorption bands of Nd3+ ions in fluoroindate glass and error calculation in experimental oscillator strength and intensity parameters

2015 ◽  
Vol 634 ◽  
pp. 6-11
Author(s):  
A. Flórez
Keyword(s):  
Heat Treatment ◽  
Oscillator Strength ◽  
Absorption Bands ◽  
Error Calculation ◽  
Intensity Parameters

Composition Dependence of the Judd-Ofelt Intensity Parameters in TeO2-PbF2: Tm3+ Glasses

2004 ◽  
Vol 829 ◽  
Author(s):  
Idris Kabalci ◽  
Gonul Ozen ◽  
Adnan Kurt ◽  
Alphan Sennaroglu
Keyword(s):  
Cross Sections ◽  
Composition Dependence ◽  
Strong Dependence ◽  
Local Environment ◽  
Ground Level ◽  
Absorption Bands ◽  
Intensity Parameters ◽  
Nir Absorption ◽  
Doped Glasses ◽  
Absorption Measurements

ABSTRACTTm3+ -doped glasses with the composition of (1-x)TeO2-xPbF2, where x=10, 15, 20, 25 mol.% were synthesized and, their thermal and absorption measurements were investigated. All the glasses were transparent. The absorption bands corresponding to the absorption of the 1G4, 3F2, 3F3, 3F4, 3H5, and 3H4 levels from the 3H6 ground level of the Tm3+ ion were observed in the optical UV/VIS/NIR absorption measurements. We calculated the integrated absorption cross sections of each band except that of 3H5 level was found to vary with composition of the PbF2. The absorption measurements were first made to determine the spontaneous emission probabilities of the 4f-4f transitions of the Tm3+ ions. The calculations were made by using the Judd - Ofelt theory. The Ω2 parameter shows the strongest dependence on the host composition and it increases with the increasing PbF2 amount. The values Ω4 increases rather slowly while the value of Ω6 is practically independent of the composition. The strong dependence of the parameter Ω2 indicates that this parameter is related to the structural change and symmetry of the local environment of the Tm3+ ions in this glass.

scholarly journals Synthesis and properties of nanocomposites based on zinc phosphate and fumed silica

Surface ◽  
2020 ◽  
Vol 12(27) ◽  
pp. 179-192
Author(s):  
V. M. Bogatyrov ◽  
◽  
M. V. Borysenko ◽  
M. V. Galaburda ◽  
O. I. Oranska ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Phosphoric Acid ◽  
Fumed Silica ◽  
Zinc Acetate ◽  
Zinc Phosphate ◽  
Absorption Bands ◽  
Simple Method ◽  
Air Drying ◽  
Orthorhombic Modification ◽  
Pyrogenic Silica

The aim of the work was to synthesize nanocomposites based on pyrogenic silica and zinc phosphate by a simple method without using a large amount of solvent and to study the characteristics and properties of the obtained materials. The dual systems of zinc phosphate/pyrogenic silica with the different ratio of components were synthesized via mechanical grinding in a porcelain drum ball mill of fumed silica (Orysyl A-380), zinc acetate (Zn(CH3COO)2·2H2O) and phosphoric acid with distilled water, followed by air-drying in an oven at 125 °C (2 h) and calcination in a muffle oven at 450 °C for 2 h. The zinc phosphate content was 0.1, 0.2, and 0.3 mmol per 1 g of SiO2. The control sample (ZP-K) was synthesized by thermal treatment of the precipitate, formed after mixing on a magnetic stirrer an aqueous solution of zinc acetate with the addition dropwise of phosphoric acid, without the use of SiO2. X-ray diffraction studies of the nanocomposites confirmed the formation of the crystalline phase of Zn3(PO4)2·4H2O (orthorhombic modification) both in the silica-containing and control ZP-K samples after air drying at 125 °C, while heat treatment at 450 °C leaded to the formation of the anhydrous monoclinic Zn3(PO4)2 phase. The content of the zinc phosphate in the dual composites was 0.1, 0.2, and 0.3 mmol per 1 g of SiO2. The IR spectra of the nanocomposites indicated the presence of absorption bands in the range of 3760-3600 cm-1, which were attributed to the unequal structural ‒OH groups of silicon and phosphorus atoms. It was found that the presence of zinc phosphate on the SiO2 surface does not cause the chemical interaction with silica during heat treatment of composites in air even at 900-1000 °C. It was shown that the ability of Zn3(PO4)2/SiO2 composites to adsorb water vapor decreases with increasing amount of modifying compound. The effect of the obtained phosphorus-containing nanocomposite on the thermal stability of an alkyd polymer matrix was considered.

scholarly journals Spectral and Transmittance Properties of Er3+ Doped Zinc Lithium Lead Calcium Borophosphate Glasses

2021 ◽  
Vol 9 (12) ◽  
pp. 636-643
Author(s):  
S. L. Meena
Keyword(s):  
Optical Absorption ◽  
Emission Cross Section ◽  
Branching Ratio ◽  
Life Time ◽  
Stimulated Emission ◽  
Radiative Properties ◽  
Absorption Bands ◽  
Borophosphate Glasses ◽  
Intensity Parameters ◽  
Quenching Method

Abstract: Zinc lithium lead calcium borophosphate glasses containing Er3+ in (40- x):P2O5:10ZnO:10Li2O:10PbO:10CaO:20B2O3:xEr2O3 (where x=1, 1.5,2 mol %) have been prepared by melt-quenching method. The amorphous nature of the glasses was confirmed by x-ray diffraction studies. Optical absorption, Excitation, fluorescence and Transmittance spectra were recorded at room temperature for all glass samples. Judd-Ofelt intensity parameters Ωλ (λ=2, 4, 6) are evaluated from the intensities of various absorption bands of optical absorption spectra. Using these intensity parameters various radiative properties like spontaneous emission probability, branching ratio, radiative life time and stimulated emission cross–section of various emission lines have been evaluated. Keywords: ZLLCBP Glasses, Optical Properties, Judd-OfeltTheory, Transmittance Properties.

Electronic spectral study of amino-acid complexes of Nd(III)

1983 ◽  
Vol 61 (8) ◽  
pp. 1778-1783 ◽  
Author(s):  
Ashok Kothari ◽  
Sudhindra N. Misra
Keyword(s):  
Amino Acid ◽  
Oscillator Strength ◽  
Spectral Study ◽  
Covalent Character ◽  
Spin Orbital ◽  
Orbital Interactions ◽  
Bonding Parameter ◽  
Intensity Parameters ◽  
Experimental Values ◽  
Electronic Spectral Study

Neodymium(III) complexes with histidine and diols (ethancdiol, prop-1,2-diol. but-2,3-diol, 2-butene-1,4-cliol, pent-1,5-diol, and hex-1,6-diol) of the type MAB, MA2B, and MAB2 have been synthesized and characterised. The values of Slater–Condon (Fk), Lande (ζ4f) spin orbital interactions, oscillator strength (P). and Judd–Ofelt (Tλ) intensity parameters have been calculated. Using these parameters, energies and intensities often levels in all the complexes in the region 360–920 nm have been computed. The agreement between the computed and experimental values is good. Using F2 values, the nephelauxetic ratio β, and bonding parameter b1/2 have been calculated, these infer the incidence of some covalent character in these complexes.

Tuning Surface Plasmon in Erbium-Boro-Tellurite Nanoglass via Thermal Annealing

2016 ◽  
Vol 846 ◽  
pp. 85-90
Author(s):  
Zahra Ashur Mahraz ◽  
M.R. Sahar ◽  
S.K. Ghoshal
Keyword(s):  
Heat Treatment ◽  
Surface Plasmon ◽  
Average Diameter ◽  
Ir Absorption ◽  
Ag Nps ◽  
Absorption Bands ◽  
Time Duration ◽  
Maximum Enhancement ◽  
Silver Nps ◽  
Quenching Method

The demand for tunable surface plasmon (SP) of embedded metal nanoparticles (NPs) in rare earth doped inorganic lasing glasses is ever-growing. Following melt quenching method Er3+ doped zinc-boro-tellurite glasses containing silver (Ag) NPs are prepared. Glasses are heat treated (thermally annealed) at varying temperatures and time duration to alter the NPs morphology which generates SP. The annealing assisted SP resonance mediated modification in spectral features is discerned. Samples heat treatment at 410 °C for 6 hrs duration ensures the reduction of Ag+ ions to Ago NPs. Thermally annealed glasses are characterized via XRD, UV–Vis-IR absorption, photoluminescence spectroscopy, and TEM imaging. XRD spectra confirm the amorphous nature of the glass and TEM image reveals the existence of homogeneously distributed spherically shaped silver NPs of average diameter ~4.5 nm. NPs are found to grow with the increase of both annealing time and temperature. The UV–Vis spectra exhibit seven absorption bands corresponding to 4f–4f transitions of Er3+ ions in the wavelength range of 500-650 nm. The localized SPR band is evidenced at 550 and 580 nm. Heat treatment causes a red shift of the plasmon peaks ascribed to the alteration in glass refractive index. Furthermore, the glass sample annealed for 6 hrs displays maximum enhancement in the emission intensity corresponding to the peaks centered at 536 (2H11/2→4I15/2), 550 (4S3/2→4I15/2) and 632 nm (4F9/2→4I15/2). This enhancement is primarily attributed to the local field effect of the silver NPs. Admirable features of the results suggest that our systematic method for heat treatment in tuning NPs size assisted SPR may contribute towards the development of functional glass.

Study of Alkoxide Silica Gels by Infrared Spectroscopy

1989 ◽  
Vol 43 (2) ◽  
pp. 263-267 ◽  
Author(s):  
D. L. Wood ◽  
E. M. Rabinovich
Keyword(s):  
Heat Treatment ◽  
Infrared Spectroscopy ◽  
Absorption Band ◽  
Infrared Spectra ◽  
Fumed Silica ◽  
Silica Gels ◽  
Structural Defects ◽  
Dangling Bonds ◽  
Absorption Bands

The infrared spectra of silica gels made from alkoxides are different from those made from fumed silica, and from the infrared spectra of other amorphous silicas in which the SiO2 network is relatively complete. One important feature of these spectra is the occurrence of an absorption band at 960 cm−1 due to the vibration of dangling -Si-OH bonds in the alkoxide gels, which is not present in many other silicas. There also are less well-defined absorption bands due to structural defects for the alkoxide gels, but their interpretation is speculative. Dried gels made with more concentrated reactants contain more defects, and heat treatment reduces the concentration of dangling bonds, especially above 900°C. For gels containing fluorine, two absorption bands appear at 932 and 980 cm−1, and these are interpreted as arising from terminal -SiF and -SiF2 groups, respectively.

Optical Analysis of RE3+: Boro-Fluoro-Phosphate Glasses

2010 ◽  
Vol 161 ◽  
pp. 13-41
Author(s):  
B. Sudhakar Reddy ◽  
S. Buddhudu
Keyword(s):  
Absorption Spectra ◽  
Emission Spectra ◽  
Green Emission ◽  
Phosphate Glasses ◽  
Radiative Properties ◽  
Composition Series ◽  
Absorption Bands ◽  
Intensity Parameters ◽  
Doped Glasses ◽  
Nir Emission

We report here on the preparation and optical characterization of certain rare earth (Nd3+,Tb3+,Pr3+ &Tm3+ each in 0.2 mol %) ions doped in two new series glasses in the following composition: Series A: 69.8 B2O3 – 10 P2O5 – 10(ZnO/CdO/TeO2) – 10 AlF3 Series B: 69.8 B2O3 – 10 P2O5 – 10(ZnO/CdO/TeO2) – 10 LiF By applying the Judd-Ofelt intensity parameters of Nd3+: BFP glasses, radiative properties of the emission transitions ( 4F3/2 ®4IJ=9/2, 11/2 &13/2 ) at 906, 1079 and 1349nm have been evaluated. By applying the Judd-Ofelt intensity parameters, radiative properties for Er3+ ions doped glasses, the NIR emission (4I13/2 4I15/2 ) at 1547nm , and also visible green emission (4S3/2 4I15/2 ) at 547nm have been evaluated. Measured absorption spectra of Pr3+: BFP glasses have shown eight absorption bands at 443, 469, 481, 589 , 1008, 1419, 1523 and 1930 nm which correspond to the transitions 3H4 ®3P2, 3P1, 3P0, 1D2, 1G4,3F4, 3F3 and 3F2 respectively. Absorption spectra of Tm3+: glasses have revealed five absorption bands at 466, 685, 790, 1206 and 1644 nm which corresponding to the transitions 3H6®1G4, 3F3, 3H4, 3H5 and 3F4 respectively. Pr3+: glasses, with an excitation at 442nm (3H4 ®3P2), a orange-red emission at 600 nm (1D2® 3H4) has been observed. In the case of Tm3+: glasses, upon excitation with 355nm (3H6®1D2), blue emissions at 452 nm (1D2®3F4) and at 476 nm (1G4®3H6) are observed. From the measured NIR emission spectra of Pr3+: BFP glasses, an NIR emission at 1354nm (1G4®3H5) and form Tm3+: glasses, an NIR emission (3F4®3H6) at 1809 nm are observed with an Ar+ laser (514.5 nm) as the excitation source.

Effect of heat treatment on the reflective spectrum of zinc oxide powders

2009 ◽  
Vol 24 (1) ◽  
pp. 19-23 ◽  
Author(s):  
M.M. Mikhailov ◽  
V.V. Neshchimenko ◽  
Chundong Li ◽  
Shiyu He ◽  
Dezhuang Yang
Keyword(s):  
Heat Treatment ◽  
Zinc Oxide ◽  
Spectral Reflectance ◽  
Near Infrared ◽  
Thermal Control ◽  
Infrared Region ◽  
Light Spectrum ◽  
Absorption Bands ◽  
Oxide Powders ◽  
Reflective Spectrum

To determine the optimum baking temperatures for nanopowder introduction, the variation of reflective spectrum of baked zinc oxide powders, which are used as pigments for thermal control coatings of spacecraft, has been investigated over the wavelength range of 0.225–2.5 μm after being baked at temperatures between 400 °C and 850 °C. It has been established that baking temperatures over 750 °C result in a reduction of spectral reflectance in the visible light spectrum region. This is due to the formation of absorption bands of intrinsic point defects and thus increasing the spectral reflectance in the near-infrared region. The optimum temperature is 650 °C at which the bleaching effect was observed long after heat treatment. Moreover, an increase in the reflection coefficient occurs in the regions of 380–450 nm and 1100–2500 nm in this case.

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