Hardness and Structure of Er3+:Sm3+ Co-Doped Oxychloride Zinc Tellurite Glass

2017 ◽  
Vol 268 ◽  
pp. 43-47
Author(s):  
S.N. Nazhirah Mazlan ◽  
Ramli Arifin ◽  
Sib Krishna Ghoshal
Keyword(s):  
Structural Properties ◽  
Tellurite Glass ◽  
Glass Composition ◽  
Rare Earth Ions ◽  
Host Matrix ◽  
High Performing ◽  
Co Doping ◽  
Quenching Method ◽  
Ir Bands

Glass samples with composition of (64-x)TeO2 + (x)ZnO + 15 ZnCl2 + 0.5 Sm2O3 + 0.5 Er2O3 (x = 20, 25 and 30 mol%) are prepared by melt quenching method. The season for co-doping with rare earth ions such as samarium (Sm3+) and erbium (Er3+) is to explore the feasibility of their simultaneous exploitation as high performing up-converted lasing materials. The role of varying modifier of ZnO concentration in improving the hardness and structural properties are evaluated. The density is observed to reduce and ionic packing density is augmented with increasing concentration of ZnO. Glass with 25 mol% of ZnO revealed the optimum hardness of 2830 N/mm2. Incorporation of Zn2+ into the tellurite host matrix is found to shift the IR bands position slightly without altering their intensity. Bonding vibrations corresponding to bending of TeO3 unit (784-762 cm-1), stretching of TeO4 units (678-676 cm-1) and Zn-O bonds (462-452 cm-1) are evidenced. Incorporation of ZnO as modifier is established to enhance the hardness and improved the structural properties. The proposed glass composition may be useful for industrial purposes.

Optical Properties of Oxy-Chloride Tellurite Glass: Role of Samarium Ions

2015 ◽  
Vol 1107 ◽  
pp. 437-442
Author(s):  
Sib Krishna Ghoshal ◽  
Nurul Syuhada Mohamad Zake ◽  
Ramli Arifin ◽  
Md Rahim Sahar ◽  
Md Supar Rohani ◽  
...  
Keyword(s):  
Optical Properties ◽  
Rare Earth ◽  
Metallic Nanoparticles ◽  
Tellurite Glass ◽  
Experimental Studies ◽  
Rare Earth Ions ◽  
Ion Concentrations ◽  
Co Doping ◽  
Quenching Method ◽  
Alternative Routes

. Achieving tunable optical properties of inorganic glasses via optimized doping of rare earth ions is ever-demanding in photonics. Control and inhibition of luminescence quenching, nonradiative decay and multi-phonon relaxation responsible of reduction of optical performance remains challenging. Doping/co-doping of different rare earth ions, variation of modifiers and embedding metallic nanoparticles (NPs) are thought as alternative routes to enhance optical response are still underway. We examine the influence of samarium ion concentrations on the optical properties of oxy-chlorite tellurite glasses of the form (70-x)TeO2-15MgO-5Li2O-10LiCl-xSm2O3 with 0.0 x 2.5 mol% prepared using melt-quenching method. The structural and optical characterizations are performed via X-ray diffraction (XRD), Ultraviolet-Visible (UV-Vis) absorption and photoluminescence (PL) spectroscopy. The glass density increased from 4.509 - 4.770 with the increase of Sm2O3 contents from 0.0 2.5 mol %. The XRD spectra confirm the amorphous nature of the glass. The absorption spectra exhibit nine prominent peaks corresponding to the transitions from the ground to excited states and the PL spectra reveal four peaks. The optical energy band gap for direct and indirect transitions are increased and Urbach energy decreased from 3.448 - 3.497, 3.165 - 3.232 and 0.217 - 0.175, respectively with the increase of Sm3+ ion concentrations. Furthermore, the significant enhancement in UV-Vis and PL response display the strong influence of samarium ion on optical and structural properties. The mechanism responsible for enhanced optical properties are analyzed and discussed. The results suggest that our careful experimental studies may contribute towards the development of tellurite glass based solid state lasers.

Samarium Concentration and Optical Correlation of Tellurite Glass

2015 ◽  
Vol 1107 ◽  
pp. 443-448
Author(s):  
Sib Krishna Ghoshal ◽  
Azmirawahida Zainuddin ◽  
Ramli Arifin ◽  
M.R. Sahar ◽  
Md Supar Rohani ◽  
...  
Keyword(s):  
Optical Properties ◽  
Tellurite Glass ◽  
Urbach Energy ◽  
Photonic Devices ◽  
Rare Earth Ions ◽  
Indirect Transition ◽  
Absorption Bands ◽  
Quenching Effect ◽  
Quenching Method ◽  
Inorganic Glasses

Modifying the structural and optical properties of inorganic glasses via controlled doping of various rare earth ions by inhibiting the quenching effect is a challenging task. We report the influence of samarium (Sm3+) ions concentration on enhanced optical properties of tellurite glass. A series of glasses with composition (0.80-x)TeO2 + 0.10Li2O + 0.10 Na2O + xSm2O3, where 0.0<x <0.03 mol% are prepared using melt quenching method and optical characterizations are performed. The XRD spectra confirm the amorphous nature of the glass. The Urbach energy decreases and the optical gap for both direcet and indirect transitions increases with the increse of samerium contents. The UV-Vis spectra comprised of eight absorption bands and PL spectra reveal four prominet peaks corresponding to various transitions from the ground state to the excited states of Sm3+ ion. The optical response shows significant enhancement with increasing concentration of samerium ions. Our detail experimental analyses may be useful for the development of tellurite glass based photonic devices. Keywords: Tellurite Glass, Sm3+ ions, Urbach Energy, Direct and Indirect Transition.

Thermal and Structural Properties of Erbium/Neodymium Co-Doped Lithium-Magnesium-Tellurite Glass

2015 ◽  
Vol 1107 ◽  
pp. 466-470 ◽  
Author(s):  
Ramli Arifin ◽  
S. Akmar Roslan ◽  
M.R. Sahar ◽  
S.K. Ghoshal ◽  
K. Hamzah
Keyword(s):  
Thermal Stability ◽  
Structural Properties ◽  
Tellurite Glass ◽  
Rare Earth Doping ◽  
X Ray Diffraction ◽  
Co Doping ◽  
Thermal Analyser ◽  
Differential Thermal Analyser ◽  
The Difference ◽  
Inorganic Glasses

Detailed characterizations of inorganic glasses via optimized rare earth doping/co-doping are challenging. Tellurite glasses with composition (78-x)TeO2-10Li2O-10MgO-2Nd2O3-xEr2O3, (where x = 0.4 to 2.0 mol%) are prepared by melt-quenching technique. The effects of Er2O3 concentration on the thermal stability and structural properties are examined. The X-ray diffraction pattern confirms the glassy nature of all samples. The temperature of glass transition (Tg), crystallization (Tc), melting (Tm) and the difference (Tc-Tg) are determined by differential thermal analyser (DTA). The values of Tc, Tg and Tm are found to vary in the range of 419-430 °C, 300-345 °C and 885-890 °C, respectively. The glass sample with 0.4 mol% Er2O3 shows highest thermal stability. The FTIR spectra measured in the range of 400 - 4000 cm1 exhibits two major absorption peaks around 1600 - 3600 cm1 and 900 - 1200 cm1 assigned to the stretching vibrational mode of OH and Te-OH respectively. Improvements in the optical and thermal properties due to co-doping may be useful for the development of tellurite glass based photonics.

Luminescence Features of Silver Nanoparticles Sensitized Samarium Doped Boro-Zinc Tellurite Glasses

2016 ◽  
Vol 846 ◽  
pp. 96-101
Author(s):  
Sib Krishna Ghoshal ◽  
Masni Shafie@Haron ◽  
M.R. Sahar
Keyword(s):  
Metallic Nanoparticles ◽  
Tellurite Glass ◽  
Emission Cross Section ◽  
Localized Surface Plasmon ◽  
Spectral Features ◽  
Tellurite Glasses ◽  
Ag Nps ◽  
Co Doping ◽  
Quenching Method ◽  
Average Size

Spectral features modification of rare earth (RE) doped tellurite glasses via controlled manipulation of metallic nanoparticles (NPs) is the current challenge in achieving enhanced lasing action. Triggering the localized surface plasmon resonance (SPR) of NPs in the glass generates tremendous applied interests especially in solid state lasers and nanophotonics. Despite several promising features of RE doped zinc-boro-tellurite glass, the low absorption and emission cross-section of RE ions prohibit them from fabricating efficient lasers. This drawback needed to overcome and significant enhancement of spectral features is required. Co-doping by rare earths and/or embedding metallic NPs (acts as sensitizer) are demonstrated to be the alternative route to surmount such shortcomings. Series of glass samples with composition 74TeO2–15B2O3–10ZnO– 1Sm2O3 – (x)Ag, where 0 ≤ x ≤ 0.1 mol% (in excess) are prepared using melt quenching method and the impacts of silver (Ag) NPs concentrations in altering their photoluminescence properties are inspected. The XRD spectra confirmed the amorphous nature of prepared glasses and the presence of Ag NPs are evidenced in EDX spectra. TEM micrographs revealed the distribution of Ag NPs with average size 7.2 nm. Absorption spectra revealed eight bands which most intense between 6F11/2 and 6F1/2. Photoluminescence spectra exhibited three prominent peaks corresponding to the transition from the excited state 4G5/2 to 6H5/2, 6H7/2, and 6H9/2 states, respectively. Our observation may be useful for the development of tellurite glass based nanophotonic devices.

scholarly journals Controlled physical and optical traits of magnesium-zinc sulphophosphate glass: Role of europium ions

2018 ◽  
Vol 14 ◽  
pp. 463-467
Author(s):  
Ibrahim Mohammed Danmallam ◽  
Sib Krishna Ghoshal ◽  
Ramli Ariffin ◽  
Siti Aisha Jupri ◽  
Sunita Sharma
Keyword(s):  
Optical Properties ◽  
Emission Spectra ◽  
Analytical Techniques ◽  
Photonic Devices ◽  
Rare Earth Ions ◽  
Absorption Data ◽  
Stable Glasses ◽  
Trivalent Rare Earth ◽  
Quenching Method

Trivalent rare earth ions doped sulfophosphate glasses became demanding owing to their several notable attributes that are advantageous for diverse photonic devices. To fulfil such goal, preparation of sulfophosphate glasses with optimized composition by selecting appropriate modifier and subsequent characterizations are essential. Driven by this idea, we synthesized a new series of europium (Eu3+) ions doped magnesium-zinc-sulfophosphate glasses of composition (65–x) P2O5–20MgO-15ZnSO4–xEu2O3 (x = 0.0, 0.5, 1.0, 1.5 and 2.0 mol%) using simple melt-quenching method. As-prepared glasses were characterized thoroughly at room temperature via various analytical techniques to determine the Eu2O3 concentration-dependent physical and optical properties. Transparent (pinkish) and thermally stable glasses were achieved. XRD pattern confirmed the amorphous nature of the studied glasses. Glass density was increased from 2.603 to 2.789 g/cm-3 with the increase of Eu2O3 contents from 0 to 2.0 mol%. FTIR spectra revealed the characteristics bonding vibrations (symmetric and asymmetric stretching and bending of nS (P-O), naS (P-O-P), nS (P-O-P), nS P3O, nS (P-O-P)of phosphate networks linkages. The UV-Vis-NIR spectra of the glasses disclosed six significant absorption peaks centred at 360, 380, 394, 414, 465, and 531 nm accompanied by two NIR peaks around 2091 and 2205 nm allocated to various transitions from the ground state to the excited states of Eu3+ ion. Furthermore, the optical absorption data were further used to calculate the energies of direct (2.0 to 3.85 eV) and indirect (3.74 to 5.0 eV) band gap as well as Urbach energies (0.1909 to 0.2440 eV). The photoluminescence (PL) emission spectra of glasses displayed four peaks entered at 593, 613, 654 and 701 nm assigned to the 5Do→7Fo, 5Do→7F2, 5Do→7F3 and 5Do→7F4 transitions of Eu3+ ion. The PL peak at 613 nm showed the highest emission intensity. The PL intensity was enhanced with the increase of Eu3+ content up to 1.5 mol% and quenched thereafter. It was concluded that controlled physical and optical properties can be obtained by appropriately optimizing the glass composition useful for photonic purposes.

The Structural Properties of Trivalent Rare Earth Ions (Er3+) Doped Borotellurite Glass

2014 ◽  
Vol 69 (2) ◽  
Author(s):  
E. S. Nurbaisyatul ◽  
K. Azman ◽  
H. Azhan ◽  
W. A. W. Razali ◽  
A. Noranizah
Keyword(s):  
Molar Volume ◽  
Structural Properties ◽  
Rare Earth Ions ◽  
Physical Parameters ◽  
Absorption Bands ◽  
Bending Vibrations ◽  
Laser Applications ◽  
Stretching Vibration ◽  
Trivalent Rare Earth ◽  
Quenching Method

Six samples of borotellurite glasses with system (80-x)TeO2- 10B2O3 - 10PbO - xEr2O3 (x=0.0, 0.5, 1.0, 1.5, 2.0, 2.5 mol%) have been prepared by using the conventional melt-quenching method. Some basic physical parameters such as density and molar volume were measured. The result reveals that the density and molar volume increases with the increases of mol% of Er2O3. The amorphous nature of the glass has been characterized using X-ray Diffraction (XRD) and all glasses are found to be amorphous in nature. The structure was analysed by FTIR spectroscopy. The FTIR spectra were recorded at room temperature in the frequency range from 650 to 4000  cm-1 using Attenuated Total Reflectance (ATR) method. From the IR results, the absorption bands were found to be in the range 667-669 cm-1, 710-712 cm-1, 880-887 cm-1, 981-997 cm-1 and 1190-1204 cm-1 which correspond to the stretching and bending vibrations mode. The absorption peaks around 1386-1388 cm-1 and 3741-3748 cm-1 which ascribed to the hydroxyl-metal bond and hydroxyl-hydrogen bond stretching vibration also have been observed. The FTIR results demonstrate that the existing of erbium in the composition leads to good structural properties thus creating potential for this glass in laser applications.

Semantic And Structural Properties Of The Banking And Financial Terminology Of The Uzbek Language

2020 ◽  
Vol 2 (08) ◽  
pp. 610-617
Author(s):  
Ekaterina Turakulovna Shirinova
Keyword(s):  
Structural Analysis ◽  
Structural Properties ◽  
Human Factor

This article discusses information on the study of terminology in Uzbek and world linguistics. Thematic grouping of banking and financial terms, which play an important role in Uzbek language vocabulary, is considered. The author gives the criteria for the distribution of terms into thematic groups, their peculiar properties examples to substantiate the hypothesis. The paradigmatic relations between the terms of this sphere are indicated. A structural analysis of the banking and financial terms of the Uzbek language is carried out.  On the basis of the anthropocentric approach, the role of the human factor in the banking and financial terminology of the Uzbek language is studied. Cognitive metaphors that exist in the terminology are considered.

scholarly journals Dynamical evolution of multiple-population globular clusters

2021 ◽  
Vol 502 (3) ◽  
pp. 4290-4304
Author(s):  
Enrico Vesperini ◽  
Jongsuk Hong ◽  
Mirek Giersz ◽  
Arkadiusz Hypki
Keyword(s):  
Structural Properties ◽  
Globular Clusters ◽  
First Generation ◽  
Radial Profile ◽  
Dynamical Evolution ◽  
Evolutionary Phase ◽  
Dynamical Parameters ◽  
Energy Equipartition

ABSTRACT We have carried out a set of Monte Carlo simulations to study a number of fundamental aspects of the dynamical evolution of multiple stellar populations in globular clusters with different initial masses, fractions of second generation (2G) stars, and structural properties. Our simulations explore and elucidate: (1) the role of early and long-term dynamical processes and stellar escape in the evolution of the fraction of 2G stars and the link between the evolution of the fraction of 2G stars and various dynamical parameters; (2) the link between the fraction of 2G stars inside the cluster and in the population of escaping stars during a cluster’s dynamical evolution; (3) the dynamics of the spatial mixing of the first-generation (1G) and 2G stars and the details of the structural properties of the two populations as they evolve toward mixing; (4) the implications of the initial differences between the spatial distribution of 1G and 2G stars for the evolution of the anisotropy in the velocity distribution and the expected radial profile of the 1G and 2G anisotropy for clusters at different stages of their dynamical history; and (5) the variation of the degree of energy equipartition of the 1G and the 2G populations as a function of the distance from the cluster’s centre and the cluster’s evolutionary phase.

scholarly journals Structural and Technological Approach to Reveal the Role of the Lipid Phase in the Formation of Soy Emulsion Gels with Chia Oil

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 48
Author(s):  
Ana M. Herrero ◽  
Claudia Ruiz-Capillas
Keyword(s):  
Raman Spectroscopy ◽  
Structural Properties ◽  
Structural Changes ◽  
Protein Secondary Structure ◽  
Lipid Phase ◽  
Α Helix ◽  
Β Sheet ◽  
Shed Light ◽  
Chia Oil

Considerable attention has been paid to emulsion gels (EGs) in recent years due to their interesting applications in food. The aim of this work is to shed light on the role played by chia oil in the technological and structural properties of EGs made from soy protein isolates (SPI) and alginate. Two systems were studied: oil-free SPI gels (SPI/G) and the corresponding SPI EGs (SPI/EG) that contain chia oil. The proximate composition, technological properties (syneresis, pH, color and texture) and structural properties using Raman spectroscopy were determined for SPI/G and SPI/EG. No noticeable (p > 0.05) syneresis was observed in either sample. The pH values were similar (p > 0.05) for SPI/G and SPI/EG, but their texture and color differed significantly depending on the presence of chia oil. SPI/EG featured significantly lower redness and more lightness and yellowness and exhibited greater puncture and gel strengths than SPI/G. Raman spectroscopy revealed significant changes in the protein secondary structure, i.e., higher (p < 0.05) α-helix and lower (p < 0.05) β-sheet, turn and unordered structures, after the incorporation of chia oil to form the corresponding SPI/EG. Apparently, there is a correlation between these structural changes and the textural modifications observed.

Kinematical evolution of Globular Clusters

2019 ◽  
Vol 14 (S351) ◽  
pp. 524-527
Author(s):  
Maria A. Tiongco ◽  
Enrico Vesperini ◽  
Anna Lisa Varri
Keyword(s):  
Angular Momentum ◽  
Structural Properties ◽  
Globular Clusters ◽  
Velocity Dispersion ◽  
Three Dimensional ◽  
Stellar Populations ◽  
Velocity Space ◽  
Fundamental Understanding

AbstractWe present several results of the study of the evolution of globular clusters’ internal kinematics, as driven by two-body relaxation and the interplay between internal angular momentum and the external Galactic tidal field. Via a large suite of N-body simulations, we explored the three-dimensional velocity space of tidally perturbed clusters, by characterizing their degree of velocity dispersion anisotropy and their rotational properties. These studies have shown that a cluster’s kinematical properties contain distinct imprints of the cluster’s initial structural properties, dynamical history, and tidal environment. Building on this fundamental understanding, we then studied the dynamics of multiple stellar populations in globular clusters, with attention to the largely unexplored role of angular momentum.

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