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.

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.

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.

Reduced electrical resistivity of reaction-sintered SiC by nitrogen doping

2008 ◽  
Vol 23 (4) ◽  
pp. 1020-1025 ◽  
Author(s):  
Young-Sam Jeon ◽  
Hyunho Shin ◽  
Young-Hyun Lee ◽  
Sang-Won Kang
Keyword(s):  
Heat Treatment ◽  
Electrical Resistivity ◽  
Photoelectron Spectroscopy ◽  
Nitrogen Doping ◽  
Nitrogen Atmosphere ◽  
X Ray Diffraction ◽  
Post Heat Treatment ◽  
X Ray ◽  
Sic Particles ◽  
Transmission Electron

A post heat treatment of reaction-sintered SiC at 1700 °C in nitrogen atmosphere significantly reduced electrical resistivity. A trace of insulating Si3N4 phase was detected via nitrogen heat treatment in high-resolution transmission electron microscopy observation; however, based on x-ray photoelectron spectroscopy, the evidence of nitrogen doping into SiC lattice has been claimed as the mechanism to the decreased resistivity. The increase of the total volume of SiC was apparent in x-ray diffraction during the nitrogen heat treatment, which was interpreted to stem from the growth of the nitrogen-doped intergranular SiC particles and surface doping of the primary SiC to reduce the contact resistance between the primary SiC particles.

Adsorption and Thermal Decomposition of Tetrakis(dimethylamido)titanium on Si and SiO2/Si Surfaces: an XPS Study

1995 ◽  
Vol 60 (3) ◽  
pp. 372-382 ◽  
Author(s):  
Michaela Janovská ◽  
Zdeněk Bastl
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Multiple Bond ◽  
Photoelectron Spectra ◽  
Surface Species ◽  
Oxide Formation ◽  
Si Substrate ◽  
X Ray ◽  
Nitride Coatings ◽  
Xps Study

X-Ray photoelectron spectroscopy (XPS) has been used to study adsorption of tetrakis(dimethylamido)titanium (TDMT) on a clean Si surface and surface on which an oxide layer was grown prior to TDMT adsorption. Measurements were carried out at temperatures 80 and 295 K. In addition, decomposition of TDMT on the above substrates yielding titanium nitride coatings was investigated. The change in surface composition as a function of TiNx layer thickness was monitored by XPS. Adsorption at 80 K proceeds without dissociation on both substrates. Photoelectron spectra measured at 295 K indicate presence of surface species containing C-N multiple bond on both substrates and on SiO2/Si substrate formation of species that contain Ti-N-C rings. At 580 K an overlayer consisting predominantly of TiNx was produced by pyrolysis of TDMT. The photoelectron spectra revealed also presence of species with C-N-C, Si-CHx and Ti-C bonds the concentration of which depended on an overlayer thickness. On SiO2/Si substrate decomposition of SiO2 accompanied by titanium oxide formation occurs during initial stages of TDMT pyrolysis.

Effect of heat treatment on structure, surface composition, infrared emission and surface electrical properties of tourmaline

2017 ◽  
Vol 31 (04) ◽  
pp. 1750026 ◽  
Author(s):  
Dengliang He ◽  
Shuxin Liu
Keyword(s):  
Heat Treatment ◽  
Electrical Properties ◽  
Zeta Potential ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Functional Materials ◽  
Infrared Emission ◽  
X Ray ◽  
Emission Properties ◽  
Structure Surface

Crystal structure, surface composition, infrared emission properties and surface electrical properties of tourmaline from Guangxi of China, when subjected to heat treatment in air atmosphere had been studied by some methods, including X-ray fluorescence spectrum (XRF), X-ray diffraction (XRD) meter, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), energy dispersion spectroscopy (EDS), scanning electron microscope (SEM) and Zeta potential analyzer, etc. Experimental results show that the unit cell of tourmaline would shrink during heat treatment because Fe[Formula: see text] were oxidized. Moreover, the Fe[Formula: see text]/Fe[Formula: see text] inside tourmaline can be raised after treatment. Infrared normal total emissivity of tourmaline reaches 0.87, and infrared radiation energy density is [Formula: see text]. It can maintain excellent infrared emission properties at high temperature. Simultaneously, tourmaline presents negative Zeta potential in the aqueous solution, and its Zeta potential reaches −18.04 mV. Zeta potential of tourmaline was increased to −24.83 mV after heat treatment at 400[Formula: see text]C, and decrease to −11.78 mV after heat treatment at 600[Formula: see text]C. These findings may provide reference data for tourmaline’s application in the field of functional materials.

CO2 Reduction to Propanol by Copper Foams: A Pre- and Post-Catalysis Study

2020 ◽  
Author(s):  
Jennifer A. Rudd ◽  
Ewa Kazimierska ◽  
Louise B. Hamdy ◽  
Odin Bain ◽  
Sunyhik Ahn ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Photoelectron Spectroscopy ◽  
Carbon Capture ◽  
Surface Composition ◽  
Co2 Reduction ◽  
Structural Rearrangement ◽  
Copper Electrode ◽  
Ex Situ ◽  
X Ray ◽  
Copper Electrodes

The utilization of carbon dioxide is a major incentive for the growing field of carbon capture. Carbon dioxide could be an abundant building block to generate higher value products. Herein, we describe the use of porous copper electrodes to catalyze the reduction of carbon dioxide into higher value products such as ethylene, ethanol and, notably, propanol. For <i>n</i>-propanol production, faradaic efficiencies reach 4.93% at -0.83 V <i>vs</i> RHE, with a geometric partial current density of -1.85 mA/cm<sup>2</sup>. We have documented the performance of the catalyst in both pristine and urea-modified foams pre- and post-electrolysis. Before electrolysis, the copper electrode consisted of a mixture of cuboctahedra and dendrites. After 35-minute electrolysis, the cuboctahedra and dendrites have undergone structural rearrangement. Changes in the interaction of urea with the catalyst surface have also been observed. These transformations were characterized <i>ex-situ</i> using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. We found that alterations in the morphology, crystallinity, and surface composition of the catalyst led to the deactivation of the copper foams.

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.

scholarly journals Dual Light- and pH-Responsive Composite of Polyazo-Derivative Grafted Cellulose Nanocrystals

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1725 ◽  
Author(s):  
Xiaohong Liu ◽  
Ming Li ◽  
Xuemei Zheng ◽  
Elias Retulainen ◽  
Shiyu Fu
Keyword(s):  
Cellulose Nanocrystals ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
X Ray Diffraction ◽  
Responsive Materials ◽  
X Ray ◽  
Ph Response ◽  
Transmission Electron ◽  
Ft Ir ◽  
Hexyl Methacrylate

As a type of functional group, azo-derivatives are commonly used to synthesize responsive materials. Cellulose nanocrystals (CNCs), prepared by acid hydrolysis of cotton, were dewatered and reacted with 2-bromoisobuturyl bromide to form a macro-initiator, which grafted 6-[4-(4-methoxyphenyl-azo) phenoxy] hexyl methacrylate (MMAZO) via atom transfer radical polymerization. The successful grafting was supported by Fourier transform infrared spectroscopy (FT-IR) and Solid magnetic resonance carbon spectrum (MAS 13C-NMR). The morphology and surface composition of the poly{6-[4-(4-methoxyphenylazo) phenoxy] hexyl methacrylate} (PMMAZO)-grafted CNCs were confirmed with Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The grafting rate on the macro-initiator of CNCs was over 870%, and the polydispersities of branched polymers were narrow. The crystal structure of CNCs did not change after grafting, as determined by X-ray diffraction (XRD). The polymer PMMAZO improved the thermal stability of cellulose nanocrystals, as shown by thermogravimetry analysis (TGA). Then the PMMAZO-grafted CNCs were mixed with polyurethane and casted to form a composite film. The film showed a significant light and pH response, which may be suitable for visual acid-alkali measurement and reversible optical storage.

Surface Composition of Free Mixed NaCl/Na2SO4 Nanoscale Aerosols Probed by X-ray Photoelectron Spectroscopy

2018 ◽  
Vol 122 (10) ◽  
pp. 2695-2702 ◽  
Author(s):  
E. Antonsson ◽  
C. Raschpichler ◽  
B. Langer ◽  
D. Marchenko ◽  
E. Rühl
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
X Ray

Surface composition and electronic structure of Ni2+xMn1−xGa studied by X-ray photoelectron spectroscopy

2006 ◽  
Vol 600 (18) ◽  
pp. 3749-3752 ◽  
Author(s):  
C. Biswas ◽  
S. Banik ◽  
A.K. Shukla ◽  
R.S. Dhaka ◽  
V. Ganesan ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
X Ray
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