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.

Optical Absorption of Erbium Doped Tellurite Glass

2014 ◽  
Vol 895 ◽  
pp. 245-249 ◽  
Author(s):  
Siti Ismail Fatimah ◽  
Md Rahim Sahar ◽  
Sib Krishna Ghoshal ◽  
R. Arifin ◽  
K. Hamzah
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Tellurite Glass ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Rare Earth Doping ◽  
X Ray Diffraction ◽  
Indirect Transition ◽  
Erbium Doped ◽  
Optical Behavior

Improving the optical behavior of tellurite glass with controlled rare earth doping is an important issue from device perspectives. The Er3+ -doped tellurite glasses having composition (75-x)TeO2-20ZnO-5Na2O-xEr2O3 where (0 x 0.7) mol% are prepared by melt quenching technique and their structural and optical properties are investigated. Amorphous nature of the samples is confirmed through X-ray diffraction technique. The optical absorption recorded at room temperature in the wavelength range from 400 to 1000 nm exhibits five broad bands. The value of the optical band gap and the Urbach energy (ΔE) are calculated from the absorption edge data. The value of optical band gap lies between 2.18 eV and 2.89 eV for the indirect transition whereas the value of Urbach energy varies from 0.15 to 0.53 eV. The optical band gap and Urbach energy values are found to dependent strongly on the erbium concentration.

Synthesis and Characterization of Polyaniline Copolymer

2012 ◽  
Vol 217-219 ◽  
pp. 551-554
Author(s):  
Ting Xi Li ◽  
Yu Hua Zhao ◽  
Qian Li ◽  
Cheng Qian Yuan ◽  
Quan Liang Chen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
The Difference ◽  
Thermal Stability Of

Abstract. Polyaniline (PANI) and p-phenylenediamine (p-PDA)-aniline copolymer were prepared via a same microemulsion method. The structures of the PANI and p-PDA-aniline copolymer were characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis（TGA）. The results revealed the difference of synthesis and characterization between PANI and p-PDA-aniline copolymer. It was shown that structure of the copolymer is almost similar to that of PANI, but the p-PDA-aniline copolymer has a better crystallization than PANI, and the thermal stability of the copolymer is higher than that of pure PANI.

Structural Study of Fe-Based Glassy Alloys with a Large Supercooled Liquid Region

2000 ◽  
Vol 644 ◽  
Author(s):  
M. Imafuku ◽  
S. Sato ◽  
T. Nakamura ◽  
H. Koshiba ◽  
E. Matsubara ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Random Network ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
X Ray Diffraction ◽  
Size Mismatch ◽  
Atomic Structures ◽  
Glassy Alloys ◽  
The Difference

AbstractThe thermal stability and local atomic structures of glassy Fe70M10B20 (M = Hf, Zr, Nb, W and Cr) alloys were analyzed by DSC, ordinary X-ray diffraction and AXS measurements. The random network of the trigonal prism-like structure of (Fe,M)3B with edge-sharing, was identified in all the Fe70M10B20 (M = Hf, Zr, Nb, W and Cr) alloys in spite of the wide variety of thermal stability upon heating. Several unique primary precipitated crystalline phases, such as Fe23B6 type and Fe-M phases, were observed in the alloys exhibiting a high thermal stability. These crystallization reactions require relatively long range rearrangements of the constituents and hence the thermal stability of the glassy phase increases, leading to the appearance of a large supercooled liquid region upon heating. These phenomena may be originated from the difference in the chemical affinity and the atomic size mismatch between M and Fe or B.

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.

Antiphase Boundaries in Ordered Ni3FE Crystals

1969 ◽  
Vol 27 ◽  
pp. 62-63
Author(s):  
Y. H. Liu
Keyword(s):  
Domain Size ◽  
Antiphase Domain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardening Mechanism ◽  
Superlattice Structure ◽  
Disordered Phase ◽  
Domain Boundaries ◽  
Atomic Scattering ◽  
The Difference

Ordered Ni3Fe crystals possess a LI2 type superlattice similar to the Cu3Au structure. The difference in slip behavior of the superlattice as compared with that of a disordered phase has been well established. Cottrell first postulated that the increase in resistance for slip in the superlattice structure is attributed to the presence of antiphase domain boundaries. Following Cottrell's domain hardening mechanism, numerous workers have proposed other refined models also involving the presence of domain boundaries. Using the anomalous X-ray diffraction technique, Davies and Stoloff have shown that the hardness of the Ni3Fe superlattice varies with the domain size. So far, no direct observation of antiphase domain boundaries in Ni3Fe has been reported. Because the atomic scattering factors of the elements in NijFe are so close, the superlattice reflections are not easily detected. Furthermore, the domain configurations in NioFe are thought to be independent of the crystallographic orientations.

Selective oxidation of cyclopentene to glutaraldehyde by H2O2 over Nb-SBA-15

2021 ◽  
Author(s):  
yingmeng qi ◽  
Qi Han ◽  
li wu ◽  
Jun Li
Keyword(s):  
Structural Properties ◽  
Selective Oxidation ◽  
Mesoporous Materials ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
X Ray

A series of niobium-containing mesoporous materials Nb-SBA-15 have been prepared by sonication–impregnation and hydrothermal process. The dispersion and structural properties of niobium-containing species were systematically characterized by X-ray diffraction, scanning...

scholarly journals Enhanced thermal stability and optical and structural properties of Tm+3 ions in doped tellurite glasses for photonic use

2021 ◽  
Vol 24 ◽  
pp. 104202
Author(s):  
N. Elkhoshkhany ◽  
Samir Marzouk ◽  
M. El–Sherbiny ◽  
Sally Yousri ◽  
Mohammed S. Alqahtani ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Structural Properties ◽  
Tellurite Glasses

Local atomic structure in tetragonal pure ZrO2nanopowders

2010 ◽  
Vol 43 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Leandro M. Acuña ◽  
Diego G. Lamas ◽  
Rodolfo O. Fuentes ◽  
Ismael O. Fábregas ◽  
Márcia C. A. Fantini ◽  
...  
Keyword(s):  
Tetragonal Phase ◽  
Local Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Structures ◽  
Crystallite Sizes ◽  
Exafs Study ◽  
The Difference ◽  
X Ray Absorption ◽  
Good Agreement

The local atomic structures around the Zr atom of pure (undoped) ZrO2nanopowders with different average crystallite sizes, ranging from 7 to 40 nm, have been investigated. The nanopowders were synthesized by different wet-chemical routes, but all exhibit the high-temperature tetragonal phase stabilized at room temperature, as established by synchrotron radiation X-ray diffraction. The extended X-ray absorption fine structure (EXAFS) technique was applied to analyze the local structure around the Zr atoms. Several authors have studied this system using the EXAFS technique without obtaining a good agreement between crystallographic and EXAFS data. In this work, it is shown that the local structure of ZrO2nanopowders can be described by a model consisting of two oxygen subshells (4 + 4 atoms) with different Zr—O distances, in agreement with those independently determined by X-ray diffraction. However, the EXAFS study shows that the second oxygen subshell exhibits a Debye–Waller (DW) parameter much higher than that of the first oxygen subshell, a result that cannot be explained by the crystallographic model accepted for the tetragonal phase of zirconia-based materials. However, as proposed by other authors, the difference in the DW parameters between the two oxygen subshells around the Zr atoms can be explained by the existence of oxygen displacements perpendicular to thezdirection; these mainly affect the second oxygen subshell because of the directional character of the EXAFS DW parameter, in contradiction to the crystallographic value. It is also established that this model is similar to another model having three oxygen subshells, with a 4 + 2 + 2 distribution of atoms, with only one DW parameter for all oxygen subshells. Both models are in good agreement with the crystal structure determined by X-ray diffraction experiments.

Problems Associated with Kα Doublet in Residual Stress Measurements

1979 ◽  
Vol 23 ◽  
pp. 333-339
Author(s):  
S. K. Gupta ◽  
B. D. Cullity
Keyword(s):  
Residual Stress ◽  
Silicon Powder ◽  
Lattice Parameter ◽  
Diffraction Peak ◽  
Parameter Determination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analysis Techniques ◽  
The Difference ◽  
Similar Accuracy

Since the measurement of residual stress by X-ray diffraction techniques is dependent on the difference in angle of a diffraction peak maximum when the sample is examined consecutively with its surface at two different angles to the diffracting planes, it is important that these diffraction angles be obtained precisely, preferably with an accuracy of ± 0.01 deg. 2θ. Similar accuracy is desired in precise lattice parameter determination. In such measurements, it is imperative that the diffractometer be well-aligned. It is in the context of diffractometer alignment with the aid of a silicon powder standard free of residual stress that the diffraction peak analysis techniques described here have been developed, preparatory to residual stress determinations.

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