Effects of the laser irradiation on graphene oxide foils in vacuum and air -=SUP=-*-=/SUP=-

AbstractA Nd:YAG laser operating at 1064 nm was used to irradiate, at different intensities, graphene oxide foils placed in vacuum and in air. The laser irradiated GO foils were analysed successively by using different techniques such as 2.0 MeV alpha particle Rutherford backscattering spectrometry, X-ray photoemission spectroscopy and SEM-EDX. In particular, in vacuum irradiated graphene oxide samples the oxygen reduction has been observed with increment of the carbon content. In air irradiated GO samples an increase in oxygen has instead been highlighted. Furthermore thermal and chemical effects are induced by the photon irradiation. Results will be presented and discussed.

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Physical investigations on the radiation damage of graphene oxide by IR pulsed laser

EPJ Web of Conferences ◽

10.1051/epjconf/201816705011 ◽

2018 ◽

Vol 167 ◽

pp. 05011 ◽

Cited By ~ 5

Author(s):

Letteria Silipigni ◽

Lorenzo Torrisi ◽

Mariapompea Cutroneo

Keyword(s):

Mass Spectrometry ◽

Graphene Oxide ◽

Nd:Yag Laser ◽

Photoelectron Spectroscopy ◽

Rutherford Backscattering Spectrometry ◽

Pulsed Laser ◽

Atomic Emission ◽

Hydrogen Atoms ◽

Strong Emission ◽

X Ray

Graphene oxide foils were irradiated by Nd:YAG laser at the moderated intensities of the order of 108 W/cm2 in vacuum. Measurements of atomic emission during the laser irradiation were performed with ion collectors and mass spectrometry, demonstrating a strong emission of carbon, oxygen and hydrogen atoms. Further investigations of the irradiated graphene oxide foils were carried out on pristine and laser irradiated samples by using Rutherford backscattering spectrometry and X-ray photoelectron spectroscopy. Results indicate that graphene oxide losses oxygen and hydrogen during the irradiation, changing its carbon content and its chemical and physical properties.

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The Degree of Oxidation of Graphene Oxide

Nanomaterials ◽

10.3390/nano11030560 ◽

2021 ◽

Vol 11 (3) ◽

pp. 560

Author(s):

Alexandra Carvalho ◽

Mariana C. F. Costa ◽

Valeria S. Marangoni ◽

Pei Rou Ng ◽

Thi Le Hang Nguyen ◽

...

Keyword(s):

Graphene Oxide ◽

Ab Initio ◽

State Of The Art ◽

High Accuracy ◽

Precise Determination ◽

Photoemission Spectroscopy ◽

Pristine Graphene ◽

X Ray ◽

Degree Of Oxidation

We show that the degree of oxidation of graphene oxide (GO) can be obtained by using a combination of state-of-the-art ab initio computational modeling and X-ray photoemission spectroscopy (XPS). We show that the shift of the XPS C1s peak relative to pristine graphene, ΔEC1s, can be described with high accuracy by ΔEC1s=A(cO−cl)2+E0, where c0 is the oxygen concentration, A=52.3 eV, cl=0.122, and E0=1.22 eV. Our results demonstrate a precise determination of the oxygen content of GO samples.

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Effects of Diode and Nd:YAG Laser Irradiation on Friction Forces Between Two Types of Ceramic Brackets and Rhodium-Coated Archwires

Journal of lasers in medical sciences ◽

10.34172/jlms.2021.13 ◽

2021 ◽

Vol 12 (1) ◽

pp. e13-e13

Author(s):

Hannaneh Ghadirian ◽

Allahyar Geramy ◽

Mohammad Ali Keshvad ◽

Soolmaz Heidari ◽

Nasim Chiniforush

Keyword(s):

Laser Irradiation ◽

Diode Laser ◽

Nd:Yag Laser ◽

Yttrium Aluminum Garnet ◽

Testing Machine ◽

Control Group ◽

Friction Forces ◽

X Ray ◽

Custom Made ◽

Ceramic Brackets

Introduction: Ceramic brackets have gained increasing popularity among dental clinicians and orthodontic patients but friction is a major concern when using them. This study sought to assess the effects of diode and Nd:YAG (neodymium-doped yttrium aluminum garnet) laser irradiation on friction forces between two types of ceramic brackets and rhodium-coated esthetic archwires. Methods: Thirty polycrystalline and 30 poly-sapphire brackets were divided into 6 groups (n=10) as follows: (I) control polycrystalline brackets (no laser irradiation), (II) polycrystalline brackets subjected to diode laser irradiation, (III) polycrystalline brackets subjected to Nd:YAG laser irradiation, (IV) control poly-sapphire brackets (no laser irradiation), (V) poly-sapphire brackets subjected to diode laser irradiation, and (VI) poly-sapphire brackets subjected to Nd:YAG laser irradiation. The bracket slots were laser-irradiated on a custom-made table. Sixty 5-cm pieces of rhodium-coated archwires were used for the friction test in a universal testing machine at a speed of 10 mm/min. Ten brackets from the six groups underwent scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX). Results: The frictional resistance value of polycrystalline brackets was significantly higher than that of poly-sapphire brackets, irrespective of laser type (P<0.05). Irradiation of diode and Nd:YAG lasers, compared with the control group, had no significant effect on friction, irrespective of bracket type (P>0.05). Conclusion: It appears that diode and Nd:YAG laser irradiation cannot significantly decrease the friction. Future studies are warranted on different laser types with variable exposure.

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Deposition of nitrides and oxides of aluminum and titanium by pulse laser irradiation

Journal of Materials Research ◽

10.1557/jmr.1992.0725 ◽

1992 ◽

Vol 7 (3) ◽

pp. 725-733 ◽

Cited By ~ 13

Author(s):

S.R. Nishitani ◽

S. Yoshimura ◽

H. Kawata ◽

M. Yamaguchi

Keyword(s):

Electron Microscopy ◽

Laser Irradiation ◽

Pulse Laser ◽

Rutherford Backscattering Spectrometry ◽

Metal Vapor ◽

Pulse Laser Irradiation ◽

X Ray ◽

Transmission Electron ◽

Ambient Gas ◽

Scanning Electron

Deposits of nitrides and oxides of Al and Ti have been produced by laser irradiation of Al and Ti targets in air, N2, and NH3 + N2 gases. Microstructure and constituent phases in these deposits have been examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and x-ray diffractometry (XRD). The distribution of metalloid elements has been investigated by Rutherford backscattering spectrometry (RBS). On the basis of the results of these examinations, the nitride and oxide deposits have been shown to be formed by reactions between ambient gas and metal-melt or metal-vapor which take place during pulse laser irradiation.

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Refinement of time‐resolved x‐ray measurement system for studying the lattice deformation of silicon under pulsed Nd:YAG laser irradiation

Review of Scientific Instruments ◽

10.1063/1.1143123 ◽

1992 ◽

Vol 63 (1) ◽

pp. 1164-1167 ◽

Cited By ~ 6

Author(s):

S. Kojima ◽

I. Maekawa ◽

S. Kawado ◽

T. Takahashi ◽

T. Ishikawa ◽

...

Keyword(s):

Laser Irradiation ◽

Measurement System ◽

Nd:Yag Laser ◽

Lattice Deformation ◽

Time Resolved ◽

Pulsed Nd:Yag Laser ◽

X Ray

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Oxidation Prevention Properties of Reduced Graphene Oxide Mixed with 1-Octanethiol-Coated Copper Nanopowder Composites

Journal of Nanomaterials ◽

10.1155/2016/1050183 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8

Author(s):

Danee Cho ◽

Dahyun Choi ◽

Youngjun Pyo ◽

Rajendra C. Pawar ◽

Yongil Kim ◽

...

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Weight Ratio ◽

Photoemission Spectroscopy ◽

Cu Nanoparticles ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Reduced Graphene ◽

Coating Layers

1-Octanethiol-coated Cu nanoparticles were mixed with reduced graphene oxide (rGO) to fabricate Cu nanoinks with enhanced oxidation prevention. Graphene oxide (GO) was synthesized using modified Hummer’s method and rGO was reduced from GO using hydrazine hydrate. Copper nanoinks were fabricated with varying concentrations of rGO (Cu : rGO ratios of 100 : 1, 500 : 1, and 1000 : 1 wt.%). The coating layers on the copper nanoparticles and rGO were observed using transmission electron microscopy and characterized by X-ray photoemission spectroscopy, X-ray diffraction, and Raman spectroscopy. It was observed that surface roughness increased as the concentration of rGO in Cu patterns increased, and an optimized Cu : rGO weight ratio of 1,000 : 1 was established. After sintering, the electrical properties and corrosion resistance of copper patterns both with and without rGO were measured and monitored for 200 days. The copper pattern with rGO (Cu : rGO = 1,000 : 1) was found to maintain its initial resistivity (1.63 × 10−7 Ω·m) for 150 days. Corrosion tests were conducted to confirm the oxidation prohibition of rGO. The resistance polarization(Rp)of the copper pattern was measured to be 1.5 times higher than that of the copper pattern without rGO. Thus, rGO was shown to prevent oxidation and improve the conductivity of copper patterns.

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Synthesis and characterization of TiN / Ti / AISI 410 coatings

Journal of Sciences and Engineering ◽

10.32829/sej.v2i1.54 ◽

2018 ◽

Vol 2 (1) ◽

pp. 7

Author(s):

S Chirino ◽

Jaime Diaz ◽

N Monteblanco ◽

E Valderrama

Keyword(s):

Synthesis And Characterization ◽

Photoemission Spectroscopy ◽

X Ray Diffraction ◽

X Ray ◽

Columnar Grains ◽

Tin Thin Films ◽

Steel Aisi ◽

Interacting Surfaces ◽

Stainless Steel Aisi

The synthesis and characterization of Ti and TiN thin films of different thicknesses was carried out on a martensitic stainless steel AISI 410 substrate used for tool manufacturing. The mechanical parameters between the interacting surfaces such as thickness, adhesion and hardness were measured. By means of the scanning electron microscope (SEM) the superficial morphology of the Ti/TiN interface was observed, finding that the growth was of columnar grains and by means of EDAX the existence of titanium was verified. Using X-ray diffraction (XRD) it was possible to observe the presence of residual stresses (~ -3.1 GPa) due to the different crystalline phases in the coating. Under X-ray photoemission spectroscopy (XPS) it was possible to observe the molecular chemical composition of the coating surface, being Ti-N, Ti-N-O and Ti-O the predominant ones.

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Stoichiometric Determination of Graphite Intercalation Compounds Using Rutherford Backscatiering Spectrometry

MRS Proceedings ◽

10.1557/proc-27-481 ◽

1983 ◽

Vol 27 ◽

Author(s):

L. Salamanca-Riba ◽

B.S. Elman ◽

M.S. Dresselhaus ◽

T. Venkatesan

Keyword(s):

Experimental Error ◽

Rutherford Backscattering Spectrometry ◽

Rutherford Backscattering ◽

Intercalation Compounds ◽

Graphite Intercalation Compounds ◽

X Ray ◽

Donor And Acceptor ◽

Graphite Intercalation ◽

Non Destructive

ABSTRACTRutherford backscattering spectrometry (RBS) is used to characterize the stoichiometry of graphite intercalation compounds (GIC). Specific application is made to several stages of different donor and acceptor compounds and to commensurate and incommensurate intercalants. A deviation from the theoretical stoichiometry is measured for most of the compounds using this non-destructive method. Within experimental error, the RBS results agree with those obtained from analysis of the (00ℓ) x-ray diffractograms and weight uptake measurements on the same samples.

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