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.

Surface analysis of a heat-treated, Al-containing, iron-based superalloy

1998 ◽  
Vol 13 (12) ◽  
pp. 3411-3416 ◽  
Author(s):  
M. F. López ◽  
A. Gutiéerrez ◽  
M. C. García-Alonso ◽  
M. L. Escudero
Keyword(s):  
Heat Treatment ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Passive Layer ◽  
Alumina Layer ◽  
Outward Diffusion ◽  
Xps Spectra ◽  
X Ray ◽  
Heat Treated ◽  
Layer Iron

The surface composition of MA 956 superalloy both as-received and after four exposure times at 1100 °C has been investigated by energy dispersive x-ray spectrometry (EDX) and x-ray photoelectron spectroscopy (XPS). The passive layer of the as-received sample is mainly formed by Cr- and Fe-oxides. Heat treatment leads to the formation of an alumina layer on which small nodules grow. XPS spectra evidence the presence of titanium and yttrium oxides at the surface of the heat-treated samples, suggesting Y and Ti outward diffusion through the alumina layer. Iron and chromium oxides at the topmost surface layers are observed only for short heat-treatment times.

XPS Study of Polyimide H-Film After Heat Treatment and Laser Processing

1989 ◽  
Vol 154 ◽  
Author(s):  
P.V. Nagarkar ◽  
E.K. Sichela ◽  
G.L. Doll
Keyword(s):  
Heat Treatment ◽  
Electrical Resistivity ◽  
Photoelectron Spectroscopy ◽  
Laser Processing ◽  
Surface Composition ◽  
Carbonyl Groups ◽  
X Ray ◽  
Heat Treated ◽  
Rapid Changes ◽  
Xps Study

AbstractAn x-ray photoelectron spectroscopy (XPS) study of laser treated and heat treated Kapton®indicates that both the treatments result in depleting the carbonyl groups from the sample and leave behind a conducting residue that still contains significant amounts of oxygen and nitrogen. The rapid changes in surface composition coincide with a substantial decrease in the electrical resistivity of the polyimide samples.

scholarly journals Photocatalytic Reduction of CO2 to Methanol Using a Copper-Zirconia Imidazolate Framework

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 346
Author(s):  
Sonam Goyal ◽  
Maizatul Shima Shaharun ◽  
Ganaga Suriya Jayabal ◽  
Chong Fai Kait ◽  
Bawadi Abdullah ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalyst Support ◽  
Oxidation Potential ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Optimum Parameters ◽  
Reduction Of Co2 ◽  
Enhanced Yield

A set of novel photocatalysts, i.e., copper-zirconia imidazolate (CuZrIm) frameworks, were synthesized using different zirconia molar ratios (i.e., 0.5, 1, and 1.5 mmol). The photoreduction process of CO2 to methanol in a continuous-flow stirred photoreactor at pressure and temperature of 1 atm and 25 °C, respectively, was studied. The physicochemical properties of the synthesized catalysts were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. The highest methanol activity of 818.59 µmol/L.g was recorded when the CuZrIm1 catalyst with Cu/Zr/Im/NH4OH molar ratio of 2:1:4:2 (mmol/mmol/mmol/M) was employed. The enhanced yield is attributed to the presence of Cu2+ oxidation state and the uniformly dispersed active metals. The response surface methodology (RSM) was used to optimize the reaction parameters. The predicted results agreed well with the experimental ones with the correlation coefficient (R2) of 0.99. The optimization results showed that the highest methanol activity of 1054 µmol/L.g was recorded when the optimum parameters were employed, i.e., stirring rate (540 rpm), intensity of light (275 W/m2) and photocatalyst loading (1.3 g/L). The redox potential value for the CuZrIm1 shows that the reduction potential is −1.70 V and the oxidation potential is +1.28 V for the photoreduction of CO2 to methanol. The current work has established the potential utilization of the imidazolate framework as catalyst support for the photoreduction of CO2 to methanol.

Low-temperature route to nanoscale P3N5 hollow spheres

2003 ◽  
Vol 18 (10) ◽  
pp. 2359-2363 ◽  
Author(s):  
Hongzhou Gu ◽  
Yunle Gu ◽  
Zhefeng Li ◽  
Yongcheng Ying ◽  
Yitai Qian
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hollow Spheres ◽  
Molar Ratio ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Influence Of Temperature On ◽  
Wide Gap ◽  
20 Nm ◽  
High Degree

Nanoscale hollow spheres of amorphous phosphorus nitride (P3N5) were synthesized by reacting PCl3 with NaN3 at 150–250 °C. Transmission electron microscope images show that the hollow spheres have a diameter of 150–350 nm, and the thickness of the shell is 20 nm. A very small amount of curly films were also found in the sample prepared at 150 °C. The infrared spectrum indicates a high degree of purity. X-ray photoelectron spectroscopy indicates the presence of P and N, with a molar ratio of 1:1.62 for P:N. Ultraviolet-visible absorption spectroscopy shows an absorption band at 265–315 nm. Under photoluminescent excitation at 230 nm, the P3N5 emits ultraviolet light at 305 nm. With a band gap of 4.28 eV, the products may be a wide gap semiconductor. A possible mechanism and the influence of temperature on the formation of the hollow spheres are also discussed.

In Situ X-Ray Diffraction Studies of Crystallization Growth Behavior in ZnO-Bi2O3-B2O3 Glass as a Route to Functional Optical Devices

MRS Advances ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 563-567 ◽  
Author(s):  
Quentin Altemose ◽  
Katrina Raichle ◽  
Brittani Schnable ◽  
Casey Schwarz ◽  
Myungkoo Kang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Xrd ◽  
Dsc Measurements ◽  
Transmission Window

ABSTRACTTransparent optical ZnO–Bi2O3–B2O3 (ZBB) glass-ceramics were created by the melt quenching technique. In this work, a melt of the glass containing stoichiometric ratios of Zn/Bi/B and As was studied. Differential scanning calorimeter (DSC) measurements was used to measure the thermal behavior. VIS/NIR transmission measurements were used to determine the transmission window. X-ray diffraction (XRD) was used to determine crystal phase. In this study, we explore new techniques and report a detailed study of in-situ XRD of the ZBB composition in order to correlate nucleation temperature, heat treatment temperature, and heat treatment duration with induced crystal phase.

Hardening of Selective Laser Melted M2 Steel

2021 ◽  
Author(s):  
Mei Yang ◽  
Yishu Zhang ◽  
Haoxing You ◽  
Richard Smith ◽  
Richard D. Sisson
Keyword(s):  
Heat Treatment ◽  
High Speed ◽  
Cutting Tools ◽  
High Speed Steel ◽  
High Hardness ◽  
Steel Part ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Near Net Shape

Abstract Selective laser melting (SLM) is an additive manufacturing technique that can be used to make the near-net-shape metal parts. M2 is a high-speed steel widely used in cutting tools, which is due to its high hardness of this steel. Conventionally, the hardening heat treatment process, including quenching and tempering, is conducted to achieve the high hardness for M2 wrought parts. It was debated if the hardening is needed for additively manufactured M2 parts. In the present work, the M2 steel part is fabricated by SLM. It is found that the hardness of as-fabricated M2 SLM parts is much lower than the hardened M2 wrought parts. The characterization was conducted including X-ray diffraction (XRD), optical microscopy, Scanning Electron Microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) to investigate the microstructure evolution of as-fabricated, quenched, and tempered M2 SLM part. The M2 wrought part was heat-treated simultaneously with the SLM part for comparison. It was found the hardness of M2 SLM part after heat treatment is increased and comparable to the wrought part. Both quenched and tempered M2 SLM and wrought parts have the same microstructure, while the size of the carbides in the wrought part is larger than that in the SLM part.

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.

EFFECT OF HEAT TREATMENT ON MICROSTRUCTURE AND CORROSION RESISTANCE OF Ni-B-W-Mo COATING DEPOSITED BY ELECTROLESS METHOD

2018 ◽  
Vol 25 (08) ◽  
pp. 1950023 ◽  
Author(s):  
ARKADEB MUKHOPADHYAY ◽  
TAPAN KUMAR BARMAN ◽  
PRASANTA SAHOO
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Electrochemical Techniques ◽  
Sodium Molybdate ◽  
Medium Carbon Steel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid Solution Strengthening ◽  
Heat Treated ◽  
Electroless Coatings

The present work reports the deposition of a quaternary Ni-B-W-Mo coating on AISI 1040 medium carbon steel and its characterization. Quaternary deposits are obtained by suitably modifying existing electroless Ni-B bath. Composition of the as-deposited coating is analyzed by energy dispersive X-ray spectroscopy. The structural aspects of the as-deposited and coatings heat treated at 300[Formula: see text]C, 350[Formula: see text]C, 400[Formula: see text]C, 450[Formula: see text]C and 500[Formula: see text]C are determined using X-ray diffraction technique. Surface of the as-deposited and heat-treated coatings is examined using a scanning electron microscope. Very high W deposition could be observed when sodium molybdate is present in the borohydride-based bath along with sodium tungstate. The coatings in their as-deposited condition are amorphous while crystallization takes place on heat treatment. A nodulated surface morphology of the deposits is also observed. Vickers’ microhardness and crystallite size measurement reveal inclusion of W and Mo results in enhanced thermal stability of the coatings. Solid solution strengthening of the electroless coatings by W and Mo is also observed. The applicability of kinetic strength theory to the hardening of the coatings on heat treatment is also investigated. Corrosion resistance of Ni-B-W-Mo coatings and effect of heat treatment on the same are also determined by electrochemical techniques.

scholarly journals Preparation and Assessment of Heat-Treated α-Chitin Nanowhiskers Reinforced Poly(viny alcohol) Film for Packaging Application

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1883 ◽  
Author(s):  
Chao Peng ◽  
Guangxue Chen
Keyword(s):  
Heat Treatment ◽  
Composite Films ◽  
Barrier Properties ◽  
Mechanical Tests ◽  
Light Transmittance ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Chitin Nanowhiskers

In this study, poly(vinyl alcohol) (PVA) composite films enhanced by α-chitin nanowhiskers (ChWs) were prepared through heat treatment. The obtained membranes were assessed by means of FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis, regular light transmittance, mechanical tests, permeability and water absorption. The influence of the nano-component and heat treatment on the mechanical, thermal and water-resistant properties of the composite membrane were analyzed. From the results of the work, the produced films with excellent barrier properties and inexpensive raw processed materials have great prospects in packaging applications.

Magnetization and XRD Studies of Laser Heat Treated SmCo5 Powders

2021 ◽  
Vol 1016 ◽  
pp. 1299-1304
Author(s):  
Naidu Seetala ◽  
Deidre Henderson ◽  
Jumel Jno-Baptiste ◽  
Hao Wen ◽  
Sheng Min Guo
Keyword(s):  
Heat Treatment ◽  
Hydrogen Gas ◽  
Vacuum Furnace ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Particles ◽  
Laser Heat ◽  
Heat Treated ◽  
Xrd Studies ◽  
Hydride Phases

The microstructure and magnetization of SmCo5 micro-particles may be used as feedstock for 3D printing to make miniature strong magnets. Thus, the magnetic response and microstructures of commercially available SmCo5 micro-particles were studied under various heat treatments using a high wattage laser. The magnetization of laser heat treated powders at 50-watt showed an increase in magnetization, while the 75-watt melt showed a little to no change. Unfortunately, the coercivity of both laser heat treated samples decreased significantly. Oxidation during the heat treatment is suspected to result in low coercivity. Purging with argon-gas prior to laser heating showed improved coercivity. To further minimize the oxidation problem a set of SmCo5 powder was reduced prior to laser heat treatment using a constant flow of hydrogen gas while being heated at various temperatures from 100 oC to 400 oC for a period of ~4 hours. The results show that the magnetization generally increases with the temperature, while the coercivity decreases significantly. Another set of SmCo5 was annealed in a vacuum furnace for one hour at temperatures between 200 oC and 400 oC in order to confirm that no hydride phases were formed during reduction. The magnetization and coercivity showed similar variations with annealing temperature to those for the reduced powders confirming that these variations may be due to change in crystal structure rather than formation of hydrides. X-ray Diffraction (XRD) studies were performed to identify the changes in crystal phases.

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