Pub Date : 2021-02-23DOI: 10.3390/COATINGS11020260
O. Rius-Ayra, N. Llorca-Isern
Recently surface modification has become necessary for the scientific community because of surface properties of new materials are usually inadequate in terms of wettability, adhesion, corrosion resistance or even drag reduction. In order to modify solid surfaces such as metals and alloys different treatments have been used to obtain a desired surface finish such as chemical vapor deposition, physical vapor deposition, chemical etching, electrodeposition or the application of non-equilibrium gaseous media, especially gaseous plasma. These treatments promote changes in roughness, hydrophobicity, biocompatibility or reactivity. Although such treatments have [...]
{"title":"Special Issue “Surface Modification of Metals and Alloys”","authors":"O. Rius-Ayra, N. Llorca-Isern","doi":"10.3390/COATINGS11020260","DOIUrl":"https://doi.org/10.3390/COATINGS11020260","url":null,"abstract":"Recently surface modification has become necessary for the scientific community because of surface properties of new materials are usually inadequate in terms of wettability, adhesion, corrosion resistance or even drag reduction. In order to modify solid surfaces such as metals and alloys different treatments have been used to obtain a desired surface finish such as chemical vapor deposition, physical vapor deposition, chemical etching, electrodeposition or the application of non-equilibrium gaseous media, especially gaseous plasma. These treatments promote changes in roughness, hydrophobicity, biocompatibility or reactivity. Although such treatments have [...]","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81239257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-21DOI: 10.3390/COATINGS11020254
Baojie Dou, Hang Xiao, Xiuzhou Lin, Yingjun Zhang, Shixiong Zhao, Song Duan, Xiulei Gao, Zhiwen Fang
Waterborne epoxy resin (WEP) has been widely used as an anti-corrosive coating for metals. However, it is still a big challenge to further improve its anti-corrosion performance due to the poor barrier properties to corrosive media. In this study, fluorinated graphene (FG) was used as a filler in WEP to improve its barrier properties, which contributes to corrosion resistance enhancement. The chemical composition and microstructures of FG and FG-modified WEP were systematically analyzed, and its corrosion resistance was also studied. Results reveal that the addition of FG sheet to WEP not only can significantly improve the tensile strength of WEP coating, but also increase the barrier properties of WEP coating and block the penetration of corrosive agent throughout the coating to the interface between coating and substrate. Meanwhile, the results also declare that the F content of FG has a significant effect on mechanical properties and long-term corrosion resistance, and the performance of FG-modified WEP coating will deteriorate with the increase of F content.
{"title":"Investigation of the Anti-Corrosion Properties of Fluorinated Graphene-Modified Waterborne Epoxy Coatings for Carbon Steel","authors":"Baojie Dou, Hang Xiao, Xiuzhou Lin, Yingjun Zhang, Shixiong Zhao, Song Duan, Xiulei Gao, Zhiwen Fang","doi":"10.3390/COATINGS11020254","DOIUrl":"https://doi.org/10.3390/COATINGS11020254","url":null,"abstract":"Waterborne epoxy resin (WEP) has been widely used as an anti-corrosive coating for metals. However, it is still a big challenge to further improve its anti-corrosion performance due to the poor barrier properties to corrosive media. In this study, fluorinated graphene (FG) was used as a filler in WEP to improve its barrier properties, which contributes to corrosion resistance enhancement. The chemical composition and microstructures of FG and FG-modified WEP were systematically analyzed, and its corrosion resistance was also studied. Results reveal that the addition of FG sheet to WEP not only can significantly improve the tensile strength of WEP coating, but also increase the barrier properties of WEP coating and block the penetration of corrosive agent throughout the coating to the interface between coating and substrate. Meanwhile, the results also declare that the F content of FG has a significant effect on mechanical properties and long-term corrosion resistance, and the performance of FG-modified WEP coating will deteriorate with the increase of F content.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81924726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-20DOI: 10.3390/COATINGS11020252
G. S. Bobadilha, C. Stokes, Katie M. Ohno, G. Kirker, Dercílio Júnior Verly Lopes, M. Nejad
Cross-laminated timber (CLT) market demand is on the rise in the United States. Adequate protective measures have not been extensively studied. The objective of this study was to investigate the weathering performance of exterior wood coatings. We evaluated coated CLT sample surfaces based on visual appearance, color change (CIE*L*a*b), gloss changes, and water intrusion. From the five exterior wood coatings evaluated, only two showed adequate performance after twelve months field exposure. Based on visual ratings following the ASTM procedures, coating failure occurs more quickly in Mississippi than in Wisconsin, due to its greater decay zone. Both location and coating type impacted the aging of the samples. Artificial weathering results were consistent with natural weathering indicating the two adequate coatings were the most resistant to failure, color, and gloss change. For future studies, new coatings designed for the protection of end-grain in CLT panels should be a target of research and development.
{"title":"Physical, Optical, and Visual Performance of Coated Cross-Laminated Timber during Natural and Artificial Weathering","authors":"G. S. Bobadilha, C. Stokes, Katie M. Ohno, G. Kirker, Dercílio Júnior Verly Lopes, M. Nejad","doi":"10.3390/COATINGS11020252","DOIUrl":"https://doi.org/10.3390/COATINGS11020252","url":null,"abstract":"Cross-laminated timber (CLT) market demand is on the rise in the United States. Adequate protective measures have not been extensively studied. The objective of this study was to investigate the weathering performance of exterior wood coatings. We evaluated coated CLT sample surfaces based on visual appearance, color change (CIE*L*a*b), gloss changes, and water intrusion. From the five exterior wood coatings evaluated, only two showed adequate performance after twelve months field exposure. Based on visual ratings following the ASTM procedures, coating failure occurs more quickly in Mississippi than in Wisconsin, due to its greater decay zone. Both location and coating type impacted the aging of the samples. Artificial weathering results were consistent with natural weathering indicating the two adequate coatings were the most resistant to failure, color, and gloss change. For future studies, new coatings designed for the protection of end-grain in CLT panels should be a target of research and development.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88294314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-18DOI: 10.3390/COATINGS11020242
M. Kowalski, A. Stachowiak
The aim of the article was to identify the effect of material hardness on the tribocorrosion process by comparing two material solutions. The analysis concerned the assessment of the process intensity and the identification of the mechanisms responsible for material loss. Possible mechanisms of tribocorrosion common for materials of high hardness were determined. Two classic material solutions (based on AISI 1045 steel) ensuring high hardness of the subsurface layers were tested: nitriding with an additional oxidation and impregnation process, and Physical Vapour Deposition (PVD) coating. In order to better identify the impact of hardness on the tribocorrosion process in each individual test, the pressures in the contact zone were increased. The tribocorrosion tests were carried out in 3.5% NaCl with free corrosion potential (OCP) for the ball-on-plate system. The results of the tribocorrosion tests presented in the article indicate that the synergy effect of friction and corrosion can be generated by the same mechanisms of material removal in both the material solutions tested. The intensity of these mechanisms is determined by material hardness. The likely mechanism of generating the synergy effect may be related to the formation of local pits along the friction path. The corrosion processes that are initiated by the cracking of the hard surface layer create local cavities, which most probably intensify frictional wear in successive time intervals. The area around the cavities facilitates plastic deformation, the initiation of cracking of the cyclically deformed layer and the tearing of larger pieces of material (especially at higher unit pressures in the frictional contact zone).
{"title":"Tribocorrosion Performance of Cr/CrN Hybrid Layer as a Coating for Machine Components Used in a Chloride Ions Environment","authors":"M. Kowalski, A. Stachowiak","doi":"10.3390/COATINGS11020242","DOIUrl":"https://doi.org/10.3390/COATINGS11020242","url":null,"abstract":"The aim of the article was to identify the effect of material hardness on the tribocorrosion process by comparing two material solutions. The analysis concerned the assessment of the process intensity and the identification of the mechanisms responsible for material loss. Possible mechanisms of tribocorrosion common for materials of high hardness were determined. Two classic material solutions (based on AISI 1045 steel) ensuring high hardness of the subsurface layers were tested: nitriding with an additional oxidation and impregnation process, and Physical Vapour Deposition (PVD) coating. In order to better identify the impact of hardness on the tribocorrosion process in each individual test, the pressures in the contact zone were increased. The tribocorrosion tests were carried out in 3.5% NaCl with free corrosion potential (OCP) for the ball-on-plate system. The results of the tribocorrosion tests presented in the article indicate that the synergy effect of friction and corrosion can be generated by the same mechanisms of material removal in both the material solutions tested. The intensity of these mechanisms is determined by material hardness. The likely mechanism of generating the synergy effect may be related to the formation of local pits along the friction path. The corrosion processes that are initiated by the cracking of the hard surface layer create local cavities, which most probably intensify frictional wear in successive time intervals. The area around the cavities facilitates plastic deformation, the initiation of cracking of the cyclically deformed layer and the tearing of larger pieces of material (especially at higher unit pressures in the frictional contact zone).","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89423646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-16DOI: 10.3390/COATINGS11020236
Q. Liang, Tianpeng Zhang, C. Zhu, Y. Bi
Riveting is the most commonly used connection method in aircraft assembly, and its quality has a crucial effect on the fatigue performance of aircraft. Many factors affect the riveting quality, among which the influence of the riveting angle and direction is not clear. In this paper, a three-dimensional finite element model of single-rivet lap joints is established and verified by the driven head geometry and the riveting force data obtained from the riveting experiments. Then, by adjusting the angle and direction of the punch in the finite element model, the riveting process is simulated at the angles of 0°, 1°, 2°, and 3° and the directions of 0° and 180° to investigate the deformation of the lap joints, the stress distribution around the hole, and the stress distribution of the rivet. Finally, the fatigue tests of the single-rivet lap joints are performed and the influence of the riveting angle and direction on the connection quality and fatigue performance of the riveting joints is analyzed.
{"title":"Effect of Riveting Angle and Direction on Fatigue Performance of Riveted Lap Joints","authors":"Q. Liang, Tianpeng Zhang, C. Zhu, Y. Bi","doi":"10.3390/COATINGS11020236","DOIUrl":"https://doi.org/10.3390/COATINGS11020236","url":null,"abstract":"Riveting is the most commonly used connection method in aircraft assembly, and its quality has a crucial effect on the fatigue performance of aircraft. Many factors affect the riveting quality, among which the influence of the riveting angle and direction is not clear. In this paper, a three-dimensional finite element model of single-rivet lap joints is established and verified by the driven head geometry and the riveting force data obtained from the riveting experiments. Then, by adjusting the angle and direction of the punch in the finite element model, the riveting process is simulated at the angles of 0°, 1°, 2°, and 3° and the directions of 0° and 180° to investigate the deformation of the lap joints, the stress distribution around the hole, and the stress distribution of the rivet. Finally, the fatigue tests of the single-rivet lap joints are performed and the influence of the riveting angle and direction on the connection quality and fatigue performance of the riveting joints is analyzed.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87458030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-16DOI: 10.3390/COATINGS11020234
K. Cui, Yingyi Zhang, T. Fu, S. Hussain, T. Saad Algarni, Jie Wang, Xu Zhang, Shafaqat Ali
Al2O3-Cr2O3 refractories are completely substitution solid solutions and can effectively resist slag erosion when used as an industrial furnace lining. In order to provide suitable chromium corundum refractory with excellent slag resistance and mechanical properties for smelting reduction ironmaking, Al2O3-Cr2O3 samples with different mass percentages (0, 10, 20, 30, 40 wt.%) of Cr2O3 were prepared by a normal pressure sintering process to study its sintering properties, mechanical properties, thermal shock resistance, and microstructure. The results of densification behavior showed that the introduction of Cr2O3 deteriorates the compactness, the relative density and volume shrinkage rate of the composite material decrease with the increase of the Cr2O3 content, and the apparent porosity increases accordingly. In terms of mechanical properties, the hardness, compressive strength, and flexural strength of Al2O3-Cr2O3 material decrease gradually with the increase of Cr2O3. After 10 and 20 thermal shock cycles, the flexural strengths of the samples all decreased. With the increase of Cr2O3 in these samples, the loss rate of flexural strength gradually increased. Considering the slag resistance and mechanical properties of the composite material, the Al2O3-Cr2O3 composite refractory with Cr2O3 content of 20–30% can meet the requirements of smelting reduction iron making kiln lining.
{"title":"Effects of Cr2O3 Content on Microstructure and Mechanical Properties of Al2O3 Matrix Composites","authors":"K. Cui, Yingyi Zhang, T. Fu, S. Hussain, T. Saad Algarni, Jie Wang, Xu Zhang, Shafaqat Ali","doi":"10.3390/COATINGS11020234","DOIUrl":"https://doi.org/10.3390/COATINGS11020234","url":null,"abstract":"Al2O3-Cr2O3 refractories are completely substitution solid solutions and can effectively resist slag erosion when used as an industrial furnace lining. In order to provide suitable chromium corundum refractory with excellent slag resistance and mechanical properties for smelting reduction ironmaking, Al2O3-Cr2O3 samples with different mass percentages (0, 10, 20, 30, 40 wt.%) of Cr2O3 were prepared by a normal pressure sintering process to study its sintering properties, mechanical properties, thermal shock resistance, and microstructure. The results of densification behavior showed that the introduction of Cr2O3 deteriorates the compactness, the relative density and volume shrinkage rate of the composite material decrease with the increase of the Cr2O3 content, and the apparent porosity increases accordingly. In terms of mechanical properties, the hardness, compressive strength, and flexural strength of Al2O3-Cr2O3 material decrease gradually with the increase of Cr2O3. After 10 and 20 thermal shock cycles, the flexural strengths of the samples all decreased. With the increase of Cr2O3 in these samples, the loss rate of flexural strength gradually increased. Considering the slag resistance and mechanical properties of the composite material, the Al2O3-Cr2O3 composite refractory with Cr2O3 content of 20–30% can meet the requirements of smelting reduction iron making kiln lining.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80024303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-09DOI: 10.3390/COATINGS11020197
Jinsu Jung, Dongjoo Bae, Sungho Kim, Hee-Dong Kim
In this work, we report the feasibility of resistive switching (RS) properties of oxygen-doped zirconium nitride (O-doped ZrN) films with platinum (Pt) and platinum silicide (PtSi) bottom electrode (BE), produced by a sputtering method. Compared to O-doped ZrN using Pt BE, when Pt/p-Si was used as BE, the foaming voltage slightly increased, but the operation current was reduced by about two orders. In particular, the average reset current of the O-doped ZrN memory cells was reduced to 50 µA, which can delay deterioration of the element, and reduces power consumption. Therefore, the use of PtSi as the BE of the O-doped ZrN films is considered highly effective in improving reliability through reduction of operating current of the memory cells.
{"title":"Reduced Operation Current of Oxygen-Doped ZrN Based Resistive Switching Memory Devices Fabricated by the Radio Frequency Sputtering Method","authors":"Jinsu Jung, Dongjoo Bae, Sungho Kim, Hee-Dong Kim","doi":"10.3390/COATINGS11020197","DOIUrl":"https://doi.org/10.3390/COATINGS11020197","url":null,"abstract":"In this work, we report the feasibility of resistive switching (RS) properties of oxygen-doped zirconium nitride (O-doped ZrN) films with platinum (Pt) and platinum silicide (PtSi) bottom electrode (BE), produced by a sputtering method. Compared to O-doped ZrN using Pt BE, when Pt/p-Si was used as BE, the foaming voltage slightly increased, but the operation current was reduced by about two orders. In particular, the average reset current of the O-doped ZrN memory cells was reduced to 50 µA, which can delay deterioration of the element, and reduces power consumption. Therefore, the use of PtSi as the BE of the O-doped ZrN films is considered highly effective in improving reliability through reduction of operating current of the memory cells.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86677577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-06DOI: 10.3390/COATINGS11020190
F. Cougnon, M. Kersemans, W. Van Paepegem, D. Depla
Due to the low heat flux towards the substrate, magnetron sputter deposition offers the possibility to deposit thin films on heat sensitive materials such as fiber-reinforced polymers, also known as composite materials. Passive thermal probe measurements during the sputter deposition of metal layers show indeed that the temperature increase remains well below 25 °C for film thicknesses up to 600 nm. The latter thickness threshold is based on the influence of embedded metal films on the adhesion of the composite plies. Films thicker than this threshold deteriorate the mechanical integrity of the composite. The introduction of the uncured composite in the vacuum chamber strongly affects the base pressure by outgassing of impurities from the composite. The impurities affect the film properties as illustrated by their impact on the Seebeck coefficient of sputter deposited thermocouples. The restrictions to embed thin films in composites, as illustrated by both the heat flux measurements, and the study on the influence of impurities, are however not insurmountable. The possibility to use embedded thin films will be briefly demonstrated in different applications such as digital volume image correlation, thermocouples, and de-icing.
{"title":"Sputter Deposited Metal Layers Embedded in Composites—From Fundamentals to Applications","authors":"F. Cougnon, M. Kersemans, W. Van Paepegem, D. Depla","doi":"10.3390/COATINGS11020190","DOIUrl":"https://doi.org/10.3390/COATINGS11020190","url":null,"abstract":"Due to the low heat flux towards the substrate, magnetron sputter deposition offers the possibility to deposit thin films on heat sensitive materials such as fiber-reinforced polymers, also known as composite materials. Passive thermal probe measurements during the sputter deposition of metal layers show indeed that the temperature increase remains well below 25 °C for film thicknesses up to 600 nm. The latter thickness threshold is based on the influence of embedded metal films on the adhesion of the composite plies. Films thicker than this threshold deteriorate the mechanical integrity of the composite. The introduction of the uncured composite in the vacuum chamber strongly affects the base pressure by outgassing of impurities from the composite. The impurities affect the film properties as illustrated by their impact on the Seebeck coefficient of sputter deposited thermocouples. The restrictions to embed thin films in composites, as illustrated by both the heat flux measurements, and the study on the influence of impurities, are however not insurmountable. The possibility to use embedded thin films will be briefly demonstrated in different applications such as digital volume image correlation, thermocouples, and de-icing.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75914370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-01DOI: 10.3390/COATINGS11030276
S. Chaluvadi, D. Mondal, C. Bigi, J. Fujii, R. Adhikari, R. Ciancio, A. Bonanni, G. Panaccione, G. Rossi, I. Vobornik, P. Orgiani
Research on ultrathin quantum materials requires full control of the growth and surface quality of the specimens in order to perform experiments on their atomic structure and electron states leading to ultimate analysis of their intrinsic properties. We report results on epitaxial FeSe thin films grown by pulsed laser deposition (PLD) on CaF2 (001) substrates as obtained by exploiting the advantages of an all-in-situ ultra-high vacuum (UHV) laboratory allowing for direct high-resolution surface analysis by scanning tunnelling microscopy (STM), synchrotron radiation X-ray photoelectron spectroscopy (XPS) and angle-resolved photoemission spectroscopy (ARPES) on fresh surfaces. FeSe PLD growth protocols were fine-tuned by optimizing target-to-substrate distance d and ablation frequency, atomically flat terraces with unit-cell step heights are obtained, overcoming the spiral morphology often observed by others. In-situ ARPES with linearly polarized horizontal and vertical radiation shows hole-like and electron-like pockets at the Γ and M points of the Fermi surface, consistent with previous observations on cleaved single crystal surfaces. The control achieved in growing quantum materials with volatile elements such as Se by in-situ PLD makes it possible to address the fine analysis of the surfaces by in-situ ARPES and XPS. The study opens wide avenues for the PLD based heterostructures as work-bench for the understanding of proximity-driven effects and for the development of prospective devices based on combinations of quantum materials.
{"title":"Direct-ARPES and STM Investigation of FeSe Thin Film Growth by Nd:YAG Laser","authors":"S. Chaluvadi, D. Mondal, C. Bigi, J. Fujii, R. Adhikari, R. Ciancio, A. Bonanni, G. Panaccione, G. Rossi, I. Vobornik, P. Orgiani","doi":"10.3390/COATINGS11030276","DOIUrl":"https://doi.org/10.3390/COATINGS11030276","url":null,"abstract":"Research on ultrathin quantum materials requires full control of the growth and surface quality of the specimens in order to perform experiments on their atomic structure and electron states leading to ultimate analysis of their intrinsic properties. We report results on epitaxial FeSe thin films grown by pulsed laser deposition (PLD) on CaF2 (001) substrates as obtained by exploiting the advantages of an all-in-situ ultra-high vacuum (UHV) laboratory allowing for direct high-resolution surface analysis by scanning tunnelling microscopy (STM), synchrotron radiation X-ray photoelectron spectroscopy (XPS) and angle-resolved photoemission spectroscopy (ARPES) on fresh surfaces. FeSe PLD growth protocols were fine-tuned by optimizing target-to-substrate distance d and ablation frequency, atomically flat terraces with unit-cell step heights are obtained, overcoming the spiral morphology often observed by others. In-situ ARPES with linearly polarized horizontal and vertical radiation shows hole-like and electron-like pockets at the Γ and M points of the Fermi surface, consistent with previous observations on cleaved single crystal surfaces. The control achieved in growing quantum materials with volatile elements such as Se by in-situ PLD makes it possible to address the fine analysis of the surfaces by in-situ ARPES and XPS. The study opens wide avenues for the PLD based heterostructures as work-bench for the understanding of proximity-driven effects and for the development of prospective devices based on combinations of quantum materials.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81116160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-31DOI: 10.3390/COATINGS11020170
Huang Songqiang, Jingzhong Zhou, Sun Kuoteng, Hailiang Yang, Cai Weichen, Yi Liu, P. Zhou, Shuangjie Wu, Hua Li
Nickel-based alloys are commonly used as protective coating materials for surface protection applications owing to their superior resistance to corrosion, wear and high-temperature oxidation. It is urgent to study the fundamental mechanism between the structure and corrosion properties of the Nickel-base composite coatings. This paper, therefore, focuses on clarifying the mechanisms of the microstructure influencing the acid corrosion and mechanical characteristics of the as-sprayed NiCrBSi coating and post-heat-treated coating. The formation mechanisms of the amorphous phase of flat particles during the plasma spray process were studied by using X-ray diffraction analysis, Raman spectroscopy and confocal laser scanning microscope at first. Then the evolutionary process of the corrosion structure and phase of the coating in the accelerated corrosion experiment is directly visualized by using scanning electron microscopy and energy spectrum analysis. The mechanical properties of the amorphous NiCrBSi coatings are lastly measured by microhardness and friction wear tests. The critical phenomena and results help to elucidate the relative influence of the surface features of atmospheric plasma sprayed coatings on acid corrosion responses and wear resistance, aiming at contributing to the development of a protective technique for electrical engineering.
{"title":"Microstructural Charactistics of Plasma Sprayed NiCrBSi Coatings and Their Wear and Corrosion Behaviors","authors":"Huang Songqiang, Jingzhong Zhou, Sun Kuoteng, Hailiang Yang, Cai Weichen, Yi Liu, P. Zhou, Shuangjie Wu, Hua Li","doi":"10.3390/COATINGS11020170","DOIUrl":"https://doi.org/10.3390/COATINGS11020170","url":null,"abstract":"Nickel-based alloys are commonly used as protective coating materials for surface protection applications owing to their superior resistance to corrosion, wear and high-temperature oxidation. It is urgent to study the fundamental mechanism between the structure and corrosion properties of the Nickel-base composite coatings. This paper, therefore, focuses on clarifying the mechanisms of the microstructure influencing the acid corrosion and mechanical characteristics of the as-sprayed NiCrBSi coating and post-heat-treated coating. The formation mechanisms of the amorphous phase of flat particles during the plasma spray process were studied by using X-ray diffraction analysis, Raman spectroscopy and confocal laser scanning microscope at first. Then the evolutionary process of the corrosion structure and phase of the coating in the accelerated corrosion experiment is directly visualized by using scanning electron microscopy and energy spectrum analysis. The mechanical properties of the amorphous NiCrBSi coatings are lastly measured by microhardness and friction wear tests. The critical phenomena and results help to elucidate the relative influence of the surface features of atmospheric plasma sprayed coatings on acid corrosion responses and wear resistance, aiming at contributing to the development of a protective technique for electrical engineering.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76863108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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