Deconvolution process approach in Raman spectra of DLC coating to determine the sp3 hybridization content using the ID/IG ratio in relation to the quantification determined by X-ray photoelectron spectroscopy

2022 ◽  
pp. 108818
Author(s):  
Elhadji Cheikh Talibouya Ba ◽  
Marcello Rosa Dumont ◽  
Paulo Sérgio Martins ◽  
Bárbara da Silva Pinheiro ◽  
Matheus Philippe Martins da Cruz ◽  
...  
Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 201
Author(s):  
Elisangela Aparecida dos Santos de Almeida ◽  
Julio Cesar Giubilei Milan ◽  
César Edil da Costa ◽  
Cristiano Binder ◽  
José Daniel Biasoli de Mello ◽  
...  

In cold rolling, a textured roll can be used to imprint a desired surface topography onto the sheet during rolling. This work proposes the use of diamond-like carbon (DLC) coatings to protect the surface topography of the rolls in replacement of the carcinogenic hard chrome. For that, hydrogenated amorphous carbon (a-C:H) was deposited on plasma nitrided tool steel, both for ground and textured specimens. Changes in surface topography due to DLC coating were assessed using a confocal microscope. Coating adhesion was evaluated using the method VDI 3198. The specimens were characterized using X-ray diffraction (XRD), microhardness test and scanning electron microscopy (SEM). The coating was characterized using Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS). The results showed a soft multilayer coating consisting of a plasma nitrided layer for load support, a Si-rich interlayer to improve adhesion and an a-C:H top layer. DLC deposition reduced the roughness of the textured specimens. The coating resulted in relatively stable friction and good durability, with small damage and negligible wear even under dry sliding.


2022 ◽  
Vol 905 ◽  
pp. 192-197
Author(s):  
Lin Lin Cai ◽  
Xiao Qing Jiang

A new composite of graphene/MoS2 is synthesized by co-exfoliation of graphite and MoS2 in isopropanol (IPA) using the organic salt potassium sodium tartrate as the assistant. The composite is characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectra. The results of TEM, XPS, and Raman spectra all illustrate that the graphene/MoS2 composite has been synthesized successfully. Furthermore, the composite is modified on glassy carbon electrode to fabricate a sensor to detect dopamine (DA). The sensor shows two linear detection ranges for DA. One is 1-45 μM and the other is 45-120 μΜ. The detection limit of the sensor (S/N=3) is 0.76 μM.


IUCrJ ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 128-135 ◽  
Author(s):  
Aroa Morán-Ruiz ◽  
Aritza Wain-Martin ◽  
Alodia Orera ◽  
María Luisa Sanjuán ◽  
Aitor Larrañaga ◽  
...  

The first fluorination of the cuspidine-related phases of Ln4(Al2O7□)O2 (where Ln = Sm, Eu, Gd) is reported. A low-temperature reaction with poly(vinylidene difluoride) lead to the fluorine being substituted in place of oxygen and inserted into the vacant position between the dialuminate groups. X-ray photoelectron spectroscopy shows the presence of the F 1s photoelectron together with an increase in Al 2p and rare-earth 4d binding energies supporting F incorporation. Energy-dispersive X-ray spectroscopy analyses are consistent with the formula Ln4(Al2O6F2)O2, confirming that substitution of one oxygen by two fluoride atoms has been achieved. Rietveld refinements show an expansion in the cell upon fluorination and confirm that the incorporation of fluoride in the Ln4(Al2O7□)O2 structure results in changes in Al coordination from four to five. Thus, the isolated tetrahedral dialuminate Al2O7 groups are converted to chains of distorted square-based pyramids. These structural results are also discussed based on Raman spectra.


1994 ◽  
Vol 349 ◽  
Author(s):  
Zhong-Min Ren ◽  
Yuan-Cheng Du ◽  
Zhi-Feng Ying ◽  
Xia-Xing Xiong ◽  
Mao-Qi He ◽  
...  

ABSTRACTFilms (with thicknesses about thousands A) of a new form of carbon allotrope, CIO also known as Fullerenes, are deposited on Si(111) substrates using ionized cluster beam deposition (ICBD) technique at low (65V) accelerating voltage V. X-ray &-20 diffraction (XRD) have been used to investigate the structural properties of C6Ofi lms, indicating hexagonal close-packed structure with strong (002) XRD assignment together with weak (100), (112) and(004) assignments. Raman spectra, X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) are carried out to make detailed studies of the electronic properties of the films and to illustrate differences between CO films and amorphous carbon films which are deposited by ICBD at high accelerating voltage V >400V. Cio soccer-balls are found to be broken into fragments as accelerating field overtakes about 400V, indicated by the results of XPS, Raman spectra, XRD, and UV/visible absorption spectra.


2001 ◽  
Vol 50 (8) ◽  
pp. 1549
Author(s):  
LI LIU-HE ◽  
ZHANG HAI-QUAN ◽  
CUI XU-MING ◽  
ZHANG YAN-HUA ◽  
XIA LI-FANG ◽  
...  

2017 ◽  
Vol 739 ◽  
pp. 23-29
Author(s):  
Wen Hsien Kao

The main purpose of this study is to research the tribological properties and mechanical properties of diamond-like carbon coating (DLC) used unbalanced magnetron sputtering system (UBMS). The objective is influence of various Zr target current on the properties of coatings, current from 0.0 A to 0.5 A. The cross-section morphology was observed by field emission scanning electron microscopy (FE-SEM). With the increase of the Zirconium targets current, the quantity contained of the Zirconium increases. Raman spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were employed to analyze the microstructure properties of the coatings. The nanoindentation tester was used to measure the mechanical properties. Furthermore, the wear tests were achieved through the Schwingung Reibung and Verschliess (SRV) reciprocating wear tester under dry condition. The DLC coating was deposited used 0.4 A Zr target current possessed the lowest I(D)/I(G) ratio, the highest sp3 content and highest hardness. The DLC coating (0.4A) also displayed excellent tibological properties including the lowest friction coefficient, and wear depth.


2010 ◽  
Vol 132 (3) ◽  
Author(s):  
T. Haque ◽  
A. Morina ◽  
A. Neville

There has been a lot of attention on the effect of lubricant additives on the friction at carbon coated surfaces. But only few papers have addressed the effect of additives on the durability of some diamondlike carbon DLC coatings. This paper presents a systematic study assessing the additive/additive and additive/surface interactions, and their influences on the durability of a low hydrogen-containing (15 at. % hydrogen) metal-free DLC coating (a-C:15H). In this study, lubricating oils containing a zinc dithiophosphate (ZDDP) antiwear additive and/or organomolybdenum friction modifiers (moly dimer and moly trimer) were used. Tribological tests were carried out in a pin-on-plate tribometer under boundary lubrication conditions. To understand the effect of additives, tribofilms formed on the wear tracks were analyzed using surface sensitive analytical techniques such as atomic force microscope, scanning electron microscopy, energy dispersive X-ray analysis, X-ray photoelectron spectroscopy, and Raman spectroscopy. Results showed that the ZDDP formed a zinc phosphate containing an ultrathin antiwear tribofilm, which offered excellent durability/wear protection to the a-C:15H coating. However, the antiwear performance of this additive was compromised when it was used with moly dimer or moly trimer. Surface analysis revealed that unlike steel surfaces, MoS2 formed on the DLC surfaces had negligible influence on friction, while the low friction DLC wear debris had strong influence on friction. Abrasive wear was found to be the dominating wear mechanism in the cases when additives showed poor wear protection on the a-C:15H coating.


2007 ◽  
Vol 127 (15) ◽  
pp. 154713 ◽  
Author(s):  
Zhongrui Li ◽  
Alexandru S. Biris ◽  
Enkeleda Dervishi ◽  
Viney Saini ◽  
Yang Xu ◽  
...  

2019 ◽  
Vol 26 (2) ◽  
pp. 143-146
Author(s):  
Jian-Ling MENG ◽  
Jian-Qi ZHU ◽  
Shun-Tian JIA ◽  
Xiao REN

By strong oxygen plasma treatment on monolayer MoS2, we observe the disappearance of the Raman modes of MoS2. We propose the hypothesis that the state of MoS2 translates from crystal to amorphous after strong oxygen plasma treatment. The evidences of no MoO3 formation shown by Raman spectra and the appearance of the Mo6+ peak and decreased O concentration shown by X-ray photoelectron spectroscopy support our hypothesis. The amorphization of monolayer MoS2 is further confirmed by the quenching of photoluminescence (PL) and the disappearance of two absorption peaks related to A, B exciton which demonstrates the disordered bandgap. Finally, we found that the amorphous MoS2 can improve the absorption fraction at the visible light (500~ 750 nm) which is potential for future visible light photocatalysis.


2018 ◽  
Vol 25 (05) ◽  
pp. 1850098
Author(s):  
WENCHANG WANG ◽  
LING ZHANG ◽  
DEJUN KONG

A diamond-like carbon (DLC) coating was deposited on YT14 cemented carbide cutting tools using an MS (magnetron sputtering), and the surface–interface morphologies, phases, and bonding energy of the obtained coatings were investigated using a scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), respectively. The wear behaviors of DLC coatings were measured using high temperature wear tests. The results show that the [Formula: see text] and [Formula: see text] appear at 284.4, and 285.3[Formula: see text]eV, respectively, the DLC coating is composed of the crystal planes (111) and (220). The average COF of DLC coatings at 750, 800, and 850[Formula: see text]C was 0.1956, 0.2082, and 0.4085, respectively, the wear depth increases with the wear temperatures increasing: At 750[Formula: see text]C, the diamond planes (111) and (222) remained, while at 800 and 850[Formula: see text]C, only the diamond plane (111) still remained, the diamond plane (220) was oxidized, resulting in wear capability decreasing. The wear mechanism was composed of abrasive wear, delamination, and oxidation wear.


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