scholarly journals Raman Spectroscopy, X-Ray, SEM, and DTA Analysis of Alkali-Phosphate Glasses ContainingWO3and Nb2O5

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
L. Bih ◽  
M. Azrour ◽  
B. Manoun ◽  
M. P. F. Graça ◽  
M. A. Valente
Keyword(s):  
Raman Spectroscopy ◽  
Phosphate Glasses ◽  
Molar Ratio ◽  
Thermal Treatments ◽  
X Ray ◽  
Heat Treated ◽  
Alkaline Oxide ◽  
Molar Amount ◽  
Dta Analysis ◽  
Quenching Method

New phosphate glasses in the quaternary system (50-x) A2O-xWO3-10 Nb2O5-40 P2O5, withx= 0; 30 and A = Li or Na were prepared by the melt quenching method. The effect on the crystallization behaviour of the glass due to the introduction of WO3into the glass composition and, consequently, the diminishing of the molar amount of the alkaline oxide and the decreasing of the molar ratio between network modifiers and network formers (M/F) was studied. The prepared glasses were heat-treated in air, at 550°C, 600°C, and 650°C for 4 hours. The structure, of the obtained samples, was studied by differential thermal analysis (DTA), X-ray powder diffraction (XRD), and Raman spectroscopy and the morphology by scanning electron microscopy (SEM). It was found that the replacement of Li2O or Na2O by WO3reduces the number of the crystallised phases. In the lithium-niobiophosphate glasses, the presence of WO3promotes the formation of NbOPO4instead of the LiNbO3phase and reduces the formation of ortho- and pyro-phosphate phases. The thermal treatments affect the arrangements of the network structure of the AW40-glasses.

scholarly journals X-Ray Diffraction and Raman Spectroscopic Studies of Glasses and Glass-Ceramics Inside the A2O-MoO3-Nb2O5-P2O5 (A= Li, Na) Systems

2010 ◽  
Vol 12 (3,4) ◽  
pp. 207
Author(s):  
H. Bih ◽  
L. Bih ◽  
M.P.F. Graça ◽  
M.A. Valente ◽  
B. Elouadi
Keyword(s):  
Glass Ceramics ◽  
Spectroscopic Studies ◽  
Phosphate Glasses ◽  
Molar Ratio ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Heat Treated ◽  
Quenching Method

<p>Phosphate glasses in the system (50-x)A<sub>2</sub>O-xMoO<sub>3</sub>-10Nb<sub>2</sub>O<sub>5</sub>-40P<sub>2</sub>O<sub>5</sub> (AMo-40), with x=0; 30 and A=Li or Na were prepared by the melt quenching method. The effect in the crystallization behaviour of the glass due to the introduction of MoO<sub>3</sub> in the glass composition and varying the molar ratio between network modifiers and network formers (M/F) was studied. The prepared glasses were heat-treated in air, at 550, 600 and 650 ºC for 4 hours. The structure, of the obtained samples, was studied by differential thermal analysis (DTA), X-ray powder diffraction (XRD), Raman spectroscopy and the morphology by scanning electron microscopy (SEM). It was found that the replacement of Li<sub>2</sub>O or Na<sub>2</sub>O by MoO<sub>3</sub> reduces the number of the crystallised phases. In the lithium-niobiophosphate glasses the presence of MoO<sub>3</sub> promotes the formation of NbOPO<sub>4</sub> and reduces the formation of ortho- and pyro-phosphate phases. The thermal treatments affect the arrangements of the network structure of the AMo-40-glasses.</p>

Study of Raman Spectroscopy on Graphene Phase from Heat Treatment of Coconut (Cocus nucifera) Shell

2015 ◽  
Vol 827 ◽  
pp. 290-293 ◽  
Author(s):  
Fandi Angga Prasetya ◽  
Muhammad Nasrullah ◽  
Ananda Yogi Nugraheni ◽  
Darminto
Keyword(s):  
Heat Treatment ◽  
Raman Spectroscopy ◽  
Atmospheric Condition ◽  
Peak Position ◽  
Special Treatment ◽  
Distilled Water ◽  
X Ray ◽  
Heat Treated ◽  
Reduced Graphene ◽  
Two Samples

Coconut (Cocus Nucifera) shell as the main ingredient in this research has been heat-treated at temperature of 1000°C in atmospheric condition aiming to obtain the expected phase of graphene. After heat treatment, an additional special treatment was given, where sample was then rinsed with distilled water. Furthermore, the heated coconut shell was characterized by Raman Spectroscopy (785 nm) and X-ray diffractometry. Based on the treatment and characterization conducted, all samples were likely to contain reduced graphene oxide (RGO) phase.The XRD data have supported the existence of RGO with the diffraction peak position (2q) at 25o and 45o. Evidence is also given by the result of Raman Spectroscopy which produces peaks (denoted by D and G bands) located at wave numbers of 1300 cm-1 and 1590 cm-1. The value of the ratio ID/IG of the two samples in the figures are 2.6 and 2.51 (matched with ratio ID/IG of RGO). The ID/IG ratio of sample which was rinsed by distilled water is higher that those without rinsing treatment.

scholarly journals Heat Treatment Effect on Eu3+ Doped TeO2-BaO-Bi2O3 Glass Systems with Ag Nanoparticles

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Tomasz Lewandowski ◽  
Michał Dembski ◽  
Michalina Walas ◽  
Marcin Łapiński ◽  
Magdalena Narajczyk ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Silver Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Rare Earth Ions ◽  
Molar Ratio ◽  
Excitation Wavelength ◽  
X Ray ◽  
Dsc Measurements ◽  
Heat Treated ◽  
Luminescence Measurement

Glass systems of 73TeO2-4BaO-3Bi2O3-2Eu2O3-xAg (in molar ratio where x = 0, 1, 2, and 3) compositions have been successfully synthesized. Silver nanoparticles were obtained with the employment of heat treatment (HT) procedure executed at 350°C. Glass transition temperatures of different compositions have been determined through DSC measurements. XRD results presented characteristic amorphous halo indicating lack of long range order in the samples. FTIR structural studies revealed that glass matrix is mainly composed of TeO3 and TeO4 species and is stable after different applied heat treatment times. X-ray photoelectron spectroscopy (XPS) measurements confirmed that in selected samples part of Ag ions changed oxidation state to form Ag0 species. TEM measurements revealed nanoparticles of size in the range of 20–40 nm. UV-vis absorption results demonstrated characteristic transitions of Eu3+ ions. Additionally, UV-vis spectra of samples heat-treated for 6, 12, 24, and 48 hours presented bands related to silver nanoparticles. Photoluminescence (PL) studies have been performed with excitation wavelength of λexc=395 nm. Obtained spectra exhibited peaks due to 5D0-7FJ (where J=2,3,4) and 5D1-7FJ (where J=1,2,3) transitions of Eu3+. Moreover, luminescence measurement indicated enhancement of rare earth ions emissions in several of the annealed samples. Increase of emission intensity of about 35% has been observed.

Investigations on electrical conduction properties and crystallization conditions of V2O5-P2O5 glass based semiconductors

2013 ◽  
Vol 1494 ◽  
pp. 215-219
Author(s):  
Akifumi Matsuda ◽  
Takuya Aoyagi ◽  
Takashi Naito ◽  
Tadashi Fujieda ◽  
Kenjiro Ikejiri ◽  
...  
Keyword(s):  
High Vacuum ◽  
Potential Candidate ◽  
X Ray Diffraction ◽  
Melt Quenching ◽  
X Ray ◽  
Heat Treated ◽  
Crystallization Conditions ◽  
Quenching Method ◽  
Vanadate Glasses ◽  
Conduction Properties

ABSTRACTWe studied the electrical properties of thermally treated V2O5-CuO-Fe2O3-P2O5 (vanadate) glasses under reducing high-vacuum conditions. The glasses were prepared by using a melt-quenching method and then applied on Al2O3 substrates as ∼40μm-thick films. The glass films were then heat treated at 375−550°C under a vacuum of 10−6 Pa. Powder X-ray diffraction showed the formation of complex oxides of both MxV2O5 (M = Cu, Fe; x = 0.12−1.3) and vanadium oxides (VOx; x = 1.5−2.5). The resistivity of the glass film crystallized at 550°C measured at 50°C and 300°C were 1.8 × 100 Ωcm and 2.8 × 10−1 Ωcm, respectively, which was 10 times lower than that of the film crystallized in air. The Seebeck coefficient was −132 μV/K at 50°C and −130 μV/K at 300°C. These results show that the vanadate glasses crystallized under the appropriate condition become potential candidate materials for semiconductor and thermoelectric application.

scholarly journals Elaboration and characterization of new phosphate glasses based on natural phosphate and red clay: influence of the chemical composition on the chemical durability

2019 ◽  
Vol 9 (3) ◽  
pp. 222-235 ◽  
Author(s):  
Oumaima Jamal Eddine ◽  
Mehdi El Bouchti ◽  
Omar Cherkaoui ◽  
Hassan Hannache ◽  
Said Gmouh
Keyword(s):  
Chemical Composition ◽  
Structural Investigation ◽  
Fluorescence Analysis ◽  
Chemical Durability ◽  
Phosphate Glasses ◽  
Red Clay ◽  
Natural Phosphate ◽  
X Ray ◽  
Quenching Method

New phosphate glass formulations based on Moroccan natural phosphate minerals alone or with Moroccan red clay additive (containing the P2O5-SiO2-CaO-Al2O3-MgO-Fe2O3-K2O-Na2O-TiO2 complex) have been successfully prepared by the quenching method. The chemical composition of each of the elaborated phosphate glasses was determined by X-ray fluorescence analysis (XRF). These investigated phosphate glasses have an excellent homogeneity as was verified by SEM. Their amorphous behavior was confirmed by XRD and DSC. The increase in density and glass transition temperature due to the addition of clay is believed to be related to the crosslinking of the phosphate chains. Structural investigation of these phosphate glasses was carried out using FTIR and Raman spectroscopies. The results obtained show that the composition of these glasses contains a mixture of ultraphosphate and polyphosphate structural units. The concentrations of this mixture depending on the initial composition of the glass components. A correlation between the chemical composition and the chemical durability of the investigated glasses was studied. The results showed that the dissolution rate of the glasses decreases by increasing the clay composition up to a point. This can be explained by assuming the formation of oxygen bridges and strong bonds within the various glasses.

Experimental Considerations and Limitations in the Application of Ultra High Temperature (2100°C) X-Ray Diffraction

1991 ◽  
Vol 35 (A) ◽  
pp. 425-429
Author(s):  
Sampath S. Iyengar
Keyword(s):  
High Temperature ◽  
Crystalline Material ◽  
Thermal Treatments ◽  
Ceramic Fibers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Controlled Atmospheres ◽  
Heat Treated ◽  
Multiple Samples

In-situ, high temperature X-ray diffraction (XRD) is an extremely useful tool for studying, monitoring or investigating crystal structure modifications as well as phase transformations in crystalline material during thermal treatments in controlled atmospheres. This technique has been used to investigate the thermal behavior of materials such as carbonate minerals, ceramic fibers, coating pigments, etc. The advantages of such a technique over the conventional practice, where samples are heat treated in a separate oven and then analyzed by XRD include: consistency of sample placement; preservation of high temperature structures to facilitate observation of metastable phases that are unstable upon exposure to outside atmosphere or during cooling; real time monitoring of reactions that occur, and products that are formed at a desired temperature or environment; and need for multiple samples or analysis.

scholarly journals Impact of Ag2O Content on the Optical and Spectroscopic Properties of Fluoro-Phosphate Glasses

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3516 ◽  
Author(s):  
Marwa Ennouri ◽  
Luukas Kuusela ◽  
Ifa Jlassi ◽  
Bernard Gelloz ◽  
Laeticia Petit ◽  
...  
Keyword(s):  
Spectroscopic Properties ◽  
Phosphate Glasses ◽  
Radiative Properties ◽  
Ligand Field ◽  
Structural And Optical Properties ◽  
Ag Nps ◽  
Heat Treated ◽  
Field Symmetry ◽  
Quenching Method ◽  
The Impact

Glasses with the system (84.60-x) NaPO3-5 ZnO-(9.40-x) NaF-x Ag2O-1 Er2O3, (x = 0, 2, 4, and 6) (mol%) were synthesized by the conventional melt-quenching method. The impact of the addition of Ag2O on the physical, thermal, structural, and optical properties of the glasses is discussed. The Judd-Oflet analysis was used to evaluate the radiative properties of the emission transitions of the glasses. The enhancement of luminescence properties due to Ag2O is discussed in terms of consequent changes in the local electromagnetic field, symmetry, and the ligand field around the Er3+ ion. The heat treatment of the glass was performed in order to precipitate Ag nanoparticles (NPs), which form as a layer at the surface of the heat-treated glasses as confirmed using scanning electron microscopy (SEM). The Ag NPs were found to increase the intensity of the emission at 1.5 µm.

Synthesis and Characterization of YCrxAl1-xO3 Particles by a Reverse Micelle Processing

2017 ◽  
Vol 47 ◽  
pp. 54-59 ◽  
Author(s):  
Dae Han Lee ◽  
Ji Young Ock ◽  
Jeong Hoon Son ◽  
Dong Sik Bae
Keyword(s):  
Reverse Micelle ◽  
Heating Temperature ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Inorganic Pigment ◽  
X Ray ◽  
Heat Treated ◽  
Average Size

YCrxAl1-xO3 nanoparticles were synthesized by a reverse micelle processing for inorganic pigment. Y(NO3)2·6H2O, Cr (NO3)2·6H2O and Al (NO3)3·9H2O are used for precursors in order to synthesis YCrxAl1-xO3 nanoparticles. The aqueous solution consists of mixing the molar ratio of Y/Cr/Al at 1:x:1-x and heat treated at 900~1300°C for 2h. The average size and distribution of synthesized YCrxAl1-xO3 powders was in the range of 10-20nm and narrow, respectively. The average size of the synthesized YCrxAl1-xO3 powders increased with increasing water to surfactant molar ratio and heating temperature. The crystallinity of synthesized YCrxAl1-xO3 powder increased with increasing heating temperature. The synthesized YCrxAl1-xO3 powders were characterized by X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM) and color spectrophotometer. The properties of the synthesized powders were affected by such variables as molar ratio, heating temperature etc.

Evolution of Microstructures and Properties of the AlxCrCuFeNi2 High-Entropy Alloys

2013 ◽  
Vol 745-746 ◽  
pp. 706-714 ◽  
Author(s):  
Sheng Guo Ma ◽  
Zhao Di Chen ◽  
Yong Zhang
Keyword(s):  
Phase Transformation ◽  
Cast Alloy ◽  
Alloy System ◽  
Molar Ratio ◽  
High Entropy Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Entropy ◽  
Heat Treated ◽  
Xrd Patterns

The microstructure and Vickers hardness of the AlxCrCuFeNi2(x=0.5, 1.0, and 2.0 in molar ratio) high-entropy alloys with as-cast and heat-treated states were investigated. X-ray diffraction (XRD) patterns suggested that for the Al0.5 alloy annealed at 900,an incomplete phase transformation from FCC to BCC occurred, while for the Al2.0 alloy as heated at 500 and 700, a converse phase transformation from BCC to FCC was obtained. Compared with the as-cast dendrites, after heat treatment, the microstructure of the alloys was obviously coarsened or spheroidized or homogenized, whereas the resultant hardness has almost not decreased even at high heating temperatures, which indicated the probability of ordering for this alloy system and thus effectively compensating the stress and structural relaxations. The Al2.0 alloy reached the maximum hardness value of 610 HV by annealing at 1100, which might be ascribed to the worm-like nanoprecipitations and the enhanced fraction of B2-ordered precipitations. By cold rolling, the Al0.5 alloy is able to reach the yield strength of 1055 MPa and the fracture strength of 1179 MPa, which was a significant improvement in comparison with the as-cast alloy.

Effect of Co Doping on the Superconducting Properties of Overdoped (Lu0.8Ca0.2)Ba2Cu3Oz

2006 ◽  
Vol 47 ◽  
pp. 108-112 ◽  
Author(s):  
Ho Keun Lee
Keyword(s):  
Thermoelectric Power ◽  
Room Temperature ◽  
Oxygen Depletion ◽  
Thermal Treatments ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Heat Treated ◽  
Power Measurements

The effect of Co-doping and thermal treatments on the superconducting properties of the heavily overdoped (Lu0.8Ca0.2)Ba2Cu3Oz has been investigated by X-ray diffraction, resistivity and thermoelectric power measurements. A comparative analysis of the resistivity and thermoelectric power of the (Lu0.8Ca0.2)Ba2(Cu3-xCox)Oz and the heat-treated Co-free (Lu0.8Ca0.2)Ba2Cu3Oz reveals that, in the overdoped region, the hole carriers reduced by the Co doping and by the oxygen depletion play a very similar role in the superconducting properties. As a result, a nearly common inverted parabolic correlation is observed between Tc and the planar carrier concentration determined from the room-temperature thermoelectric power measurements.

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