Xi Zhao, S. Lan, Lina Hu, Zhen-Duo Wu, Yaqiang Dong, Yang Ren, Xun-li Wang
By combining Differential Scanning Calorimetry and in-situ high-energy synchrotron X-ray diffraction, the sub- T g relaxation of multicomponent FeSiBPC metallic glasses (MGs) has been systematically investigated. A two-stage relaxation behaviour in a series of Fe-based MGs has been observed, indicating the pinning effect of Curie temperature. The origin of this behavior resides in the local structure departure from short-range order to medium-range order upon annealing. Analysis of diffraction and thermophysical data shows that the structural ordering involved in the β relaxation is confined and, meanwhile, facilitated by the magnetic ordering. It is mainly the medium-range rearrangements of atoms that yield the influence on magnetic ordering. This work provides new insights into the interaction between structural arrangement during relaxation and intrinsic magnetic ordering and helps to understand the inner magnet-influenced β relaxation in MGs.
{"title":"Pinning Effect of Curie Temperature in the Sub-T g Relaxation of FeSiBPC Glasses","authors":"Xi Zhao, S. Lan, Lina Hu, Zhen-Duo Wu, Yaqiang Dong, Yang Ren, Xun-li Wang","doi":"10.2139/ssrn.3937056","DOIUrl":"https://doi.org/10.2139/ssrn.3937056","url":null,"abstract":"By combining Differential Scanning Calorimetry and in-situ high-energy synchrotron X-ray diffraction, the sub- T g relaxation of multicomponent FeSiBPC metallic glasses (MGs) has been systematically investigated. A two-stage relaxation behaviour in a series of Fe-based MGs has been observed, indicating the pinning effect of Curie temperature. The origin of this behavior resides in the local structure departure from short-range order to medium-range order upon annealing. Analysis of diffraction and thermophysical data shows that the structural ordering involved in the β relaxation is confined and, meanwhile, facilitated by the magnetic ordering. It is mainly the medium-range rearrangements of atoms that yield the influence on magnetic ordering. This work provides new insights into the interaction between structural arrangement during relaxation and intrinsic magnetic ordering and helps to understand the inner magnet-influenced β relaxation in MGs.","PeriodicalId":10639,"journal":{"name":"Computational Materials Science eJournal","volume":"88 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84289345","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}
Mingxu Wang, Ke Liu, Gongji Yang, Jinfu Li, Hong Zhu, L. Kong
Abstract Designing of new alloys requires a detailed understanding of the roles played by each alloying element, yet a systematic investigation of the solid-solution strengthening effects in Ni is still missing. High throughput density functional theory calculations were therefore performed to quantitatively assess the strengthening effects of 35 potential alloying elements from the 2nd to the 6th row of the periodic table in FCC-Ni with varying concentrations. The obtained composition-dependent lattice constants and shear moduli were employed to analyze their strengthening effects within the framework of the Labusch model. It is found that the strengthening ability correlates with the position of the element on the periodic table. Elements in both ends of each period tend to have higher strengthening abilities than those in the middle, and the lattice misfit is found to dominate the strengthening effect for elements in the 5th and 6th period. Stability analysis reveals that all the solid solution models are dynamically stable and intrinsically ductile. Thermodynamic consideration finds that roughly half of the elements are prone to form solid solutions with Ni. By adopting the experimental solubilities, the strengthening potentials of these elements were further evaluated and promising strengthening elements were screened.
{"title":"Solid-Solution Strengthening Effects in Binary Ni-Based Alloys Evaluated by High-Throughput Calculations","authors":"Mingxu Wang, Ke Liu, Gongji Yang, Jinfu Li, Hong Zhu, L. Kong","doi":"10.2139/ssrn.3674679","DOIUrl":"https://doi.org/10.2139/ssrn.3674679","url":null,"abstract":"Abstract Designing of new alloys requires a detailed understanding of the roles played by each alloying element, yet a systematic investigation of the solid-solution strengthening effects in Ni is still missing. High throughput density functional theory calculations were therefore performed to quantitatively assess the strengthening effects of 35 potential alloying elements from the 2nd to the 6th row of the periodic table in FCC-Ni with varying concentrations. The obtained composition-dependent lattice constants and shear moduli were employed to analyze their strengthening effects within the framework of the Labusch model. It is found that the strengthening ability correlates with the position of the element on the periodic table. Elements in both ends of each period tend to have higher strengthening abilities than those in the middle, and the lattice misfit is found to dominate the strengthening effect for elements in the 5th and 6th period. Stability analysis reveals that all the solid solution models are dynamically stable and intrinsically ductile. Thermodynamic consideration finds that roughly half of the elements are prone to form solid solutions with Ni. By adopting the experimental solubilities, the strengthening potentials of these elements were further evaluated and promising strengthening elements were screened.","PeriodicalId":10639,"journal":{"name":"Computational Materials Science eJournal","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84138586","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}
Yuxuan Chen, A. Li, Zhiyuan Ma, Taotao Wang, Yinong Liu, Kaiyuan Yu, Feng Yang, D. Jiang, Kun Zhao, Hong Yang, Y. Ren, L. Cui
In this work, we designed a NiTiFe-Nb nanowire composite to realize a high-stability and small-hysteresis R phase two-way shape memory effect (TWSME). The R-phase TWSME was achieved in the composite in an annealed state without thermomechanical training due to the inherent internal stresses associated with the Nb nanowires, as demonstrated by in situ synchrotron high-energy X-ray diffraction. Besides, in situ transmission electron microscopy analyses revealed some details of the R-phase transformation process, which render an explanation of the high cyclic stability of the R-phase TWSME. The R-phase transformation was found to proceed over several stages, including the formation of precursor nanodomains of partial lattice distortion for the R phase, the formation of R phase particles of coordinated orientations, the coalescence of the R phase particles into selected plate variants of preferential orientations for TWSME, and the continued evolution of the R phase crystallographic structure for further TWSME with zero hysteresis. Such stage-wise process of the R-phase transformation divides the total TWSME strain into segments of smaller magnitudes in the macroscopic behavior, and more importantly reduces the discrete lattice distortion mismatch at the transformation interface on the microscopic scale. This drastically reduces the chances of generating dislocations during the transformation process, thus rendering the high cyclic stability of the R-phase TWSME.
{"title":"High-Stability and Small-Hysteresis R Phase Two-Way Shape Memory Effect of a Nitife-Nb Nanowire Composite","authors":"Yuxuan Chen, A. Li, Zhiyuan Ma, Taotao Wang, Yinong Liu, Kaiyuan Yu, Feng Yang, D. Jiang, Kun Zhao, Hong Yang, Y. Ren, L. Cui","doi":"10.2139/ssrn.3831027","DOIUrl":"https://doi.org/10.2139/ssrn.3831027","url":null,"abstract":"In this work, we designed a NiTiFe-Nb nanowire composite to realize a high-stability and small-hysteresis R phase two-way shape memory effect (TWSME). The R-phase TWSME was achieved in the composite in an annealed state without thermomechanical training due to the inherent internal stresses associated with the Nb nanowires, as demonstrated by in situ synchrotron high-energy X-ray diffraction. Besides, in situ transmission electron microscopy analyses revealed some details of the R-phase transformation process, which render an explanation of the high cyclic stability of the R-phase TWSME. The R-phase transformation was found to proceed over several stages, including the formation of precursor nanodomains of partial lattice distortion for the R phase, the formation of R phase particles of coordinated orientations, the coalescence of the R phase particles into selected plate variants of preferential orientations for TWSME, and the continued evolution of the R phase crystallographic structure for further TWSME with zero hysteresis. Such stage-wise process of the R-phase transformation divides the total TWSME strain into segments of smaller magnitudes in the macroscopic behavior, and more importantly reduces the discrete lattice distortion mismatch at the transformation interface on the microscopic scale. This drastically reduces the chances of generating dislocations during the transformation process, thus rendering the high cyclic stability of the R-phase TWSME.","PeriodicalId":10639,"journal":{"name":"Computational Materials Science eJournal","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81681620","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}
Cong-hui Liu, R. Thomas, T. Sun, J. Donoghue, Xun Zhang, T. Burnett, J. Quinta da Fonseca, M. Preuss
During service of gas turbine engines, high cycle fatigue of titanium is a leading cause of component failure highlighting the need for better understanding of the crack initiation mechanism to predict initiation sites. In this study, the relationship between plastic slip activity and fatigue crack initiation was investigated in a near-α titanium alloy using cyclic four-point bending at up to 90% of the proof stress, with the finding from surface characterization that plasticity at such low stress levels was dominated by the basal slip and two types of cracking were seen parallel to basal slip traces. Detailed 3D analysis of both crack types highlighted out-of-plane Burgers vector activity for the observed basal slip associated with crack initiation, consistent with the classic surface roughening mechanism. The transgranular crack initiation was accompanied by the formation of crystallographic facet which was identified to be 6° away from the basal plane due to additional prismatic slip activation during multi-step crack formation. The intergranular crack facet along the boundary between primary α grain pairs, which have their c-axes aligned nearly parallel to each other but with mis-aligned prismatic planes, was formed by an easy cleavage in one step along the basal plane. Statistical evaluation demonstrated that grains combining a moderately high Schmid factor for basal slip, high resolved tensile stress along the c-axis and the Burgers vector being orientated strongly out-of-surface plane favoured crack initiation. Based on those observations a new parameter involving these three geometrical factors was developed to predict surface crack initiation sites.
{"title":"Multi-Dimensional Study of the Effect of Early Slip Activity on Fatigue Crack Initiation in a Near-α Titanium Alloy","authors":"Cong-hui Liu, R. Thomas, T. Sun, J. Donoghue, Xun Zhang, T. Burnett, J. Quinta da Fonseca, M. Preuss","doi":"10.2139/ssrn.3860382","DOIUrl":"https://doi.org/10.2139/ssrn.3860382","url":null,"abstract":"During service of gas turbine engines, high cycle fatigue of titanium is a leading cause of component failure highlighting the need for better understanding of the crack initiation mechanism to predict initiation sites. In this study, the relationship between plastic slip activity and fatigue crack initiation was investigated in a near-α titanium alloy using cyclic four-point bending at up to 90% of the proof stress, with the finding from surface characterization that plasticity at such low stress levels was dominated by the basal slip and two types of cracking were seen parallel to basal slip traces. Detailed 3D analysis of both crack types highlighted out-of-plane Burgers vector activity for the observed basal slip associated with crack initiation, consistent with the classic surface roughening mechanism. The transgranular crack initiation was accompanied by the formation of crystallographic facet which was identified to be 6° away from the basal plane due to additional prismatic slip activation during multi-step crack formation. The intergranular crack facet along the boundary between primary α grain pairs, which have their c-axes aligned nearly parallel to each other but with mis-aligned prismatic planes, was formed by an easy cleavage in one step along the basal plane. Statistical evaluation demonstrated that grains combining a moderately high Schmid factor for basal slip, high resolved tensile stress along the c-axis and the Burgers vector being orientated strongly out-of-surface plane favoured crack initiation. Based on those observations a new parameter involving these three geometrical factors was developed to predict surface crack initiation sites.","PeriodicalId":10639,"journal":{"name":"Computational Materials Science eJournal","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86118906","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}
Bing Xu, D. Ji, Lizuo Wu, Lujia Zhou, Yu Liu, Zhanming Zhang, Junliang Zhang
Heck-type C-H bond activation of unactivated alkenes has emerged as a powerful strategy for the construction of synthetically valuable spirocycles over past 30 years, however, the development of asymmetric version has lagged largely behind. Herein we demonstrate a robust Heck-type reaction of a broad range of unactivated alkenes enabled by the first palladium/Xu-Phos-catalyzed tandem Heck/remote C−H bond alkylation. Moreover, both enantiomers of the product can be efficiently prepared using the same enantiomer of a chiral ligand via a position of the phenyl ring-dependent enantiodivergent synthesis. The salient features of this methodology include operational simplicity, high chemo- and enantioselectivity, broad substrate scope. In addition, we first revealed that the C(sp2)-H activation, alkene insertion and C−I reductive elimination steps are reversible by experiments.
{"title":"Article Palladium/Xu-Phos-Catalyzed Enantioselective Cascade Heck/Remote C( sp2)−H Alkylation Reaction","authors":"Bing Xu, D. Ji, Lizuo Wu, Lujia Zhou, Yu Liu, Zhanming Zhang, Junliang Zhang","doi":"10.2139/ssrn.3936039","DOIUrl":"https://doi.org/10.2139/ssrn.3936039","url":null,"abstract":"Heck-type C-H bond activation of unactivated alkenes has emerged as a powerful strategy for the construction of synthetically valuable spirocycles over past 30 years, however, the development of asymmetric version has lagged largely behind. Herein we demonstrate a robust Heck-type reaction of a broad range of unactivated alkenes enabled by the first palladium/Xu-Phos-catalyzed tandem Heck/remote C−H bond alkylation. Moreover, both enantiomers of the product can be efficiently prepared using the same enantiomer of a chiral ligand via a position of the phenyl ring-dependent enantiodivergent synthesis. The salient features of this methodology include operational simplicity, high chemo- and enantioselectivity, broad substrate scope. In addition, we first revealed that the C(sp2)-H activation, alkene insertion and C−I reductive elimination steps are reversible by experiments.","PeriodicalId":10639,"journal":{"name":"Computational Materials Science eJournal","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84090573","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}
Zhong-Zhu Li, Yu-Hao Li, D. Terentyev, N. Castin, A. Bakaev, G. Bonny, Zhangcan Yang, L. Liang, F. Gao, G. Lu
The formation of periodic arrangements of voids is an interesting phenomenon occurring in materials under neutron irradiation, usually replicating the symmetry and crystallographic orientation of the host matrix, hence called “void lattice”. Here, taking tungsten as an example, we explore the formation mechanism of the void lattice using an object kinetic Monte Carlo (OKMC) model through the collision cascades simulated using molecular dynamics method. Specifically, the detailed processes from the chaotic neutron irradiation defects to the observable void lattice are obtained via OKMC simulation, which is a prerequisite for understanding its formation mechanism. The formation of the void lattice could be divided into three stages: nucleation, incubation and growth. Both the one-dimensional (1D) migration of SIAs and the fraction of clustered vacancies in cascades play a critical role in the emergence of the void lattice. On the one hand, the 1D migration of SIAs leads to the mutual protection of voids aligned in <111> directions. The self-shielded voids may therefore grow faster compared to the unaligned ones. On the other hand, a moderate fraction of clustered vacancies in cascades guarantees a stable rate for both nucleation and growth of voids. Once the density of the <111> aligned voids reaches a critical value, the dissolution rate of the unaligned voids will overwhelm their nucleation rate, leading to the formation of void-free channels and thus the void lattice. Our results reveal the interrelated mechanism of the 1D migration of SIAs and intra-cascade vacancy clustering for the formation of the void lattice under neutron irradiation, which improves our fundamental understanding of the self-assembled microstructures in irradiated materials.
{"title":"Understanding the Formation Mechanism of Void Lattice Under Irradiation: From Collision Cascades to Self-Assembled Nanovoids","authors":"Zhong-Zhu Li, Yu-Hao Li, D. Terentyev, N. Castin, A. Bakaev, G. Bonny, Zhangcan Yang, L. Liang, F. Gao, G. Lu","doi":"10.2139/ssrn.3830973","DOIUrl":"https://doi.org/10.2139/ssrn.3830973","url":null,"abstract":"The formation of periodic arrangements of voids is an interesting phenomenon occurring in materials under neutron irradiation, usually replicating the symmetry and crystallographic orientation of the host matrix, hence called “void lattice”. Here, taking tungsten as an example, we explore the formation mechanism of the void lattice using an object kinetic Monte Carlo (OKMC) model through the collision cascades simulated using molecular dynamics method. Specifically, the detailed processes from the chaotic neutron irradiation defects to the observable void lattice are obtained via OKMC simulation, which is a prerequisite for understanding its formation mechanism. The formation of the void lattice could be divided into three stages: nucleation, incubation and growth. Both the one-dimensional (1D) migration of SIAs and the fraction of clustered vacancies in cascades play a critical role in the emergence of the void lattice. On the one hand, the 1D migration of SIAs leads to the mutual protection of voids aligned in <111> directions. The self-shielded voids may therefore grow faster compared to the unaligned ones. On the other hand, a moderate fraction of clustered vacancies in cascades guarantees a stable rate for both nucleation and growth of voids. Once the density of the <111> aligned voids reaches a critical value, the dissolution rate of the unaligned voids will overwhelm their nucleation rate, leading to the formation of void-free channels and thus the void lattice. Our results reveal the interrelated mechanism of the 1D migration of SIAs and intra-cascade vacancy clustering for the formation of the void lattice under neutron irradiation, which improves our fundamental understanding of the self-assembled microstructures in irradiated materials.","PeriodicalId":10639,"journal":{"name":"Computational Materials Science eJournal","volume":"258 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77535010","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}
Flurin D. Eisner, B. Tam, Jun Yan, V. Belova, Wesley Ow, Mohammed Azzouzi, A. Kafizas, M. C. Quiles, A. Hankin, J. Nelson
The strong but narrow-bandwidth absorption spectra of organic semiconductors make them excellent candidates for semi-transparent solar-cell applications in which colour-specificity is important. In this mainly theoretical study, we show that using a hybrid heterojunction combining the transparent inorganic semiconductor CuSCN with organic semiconductors (C70, PC70BM, C60, ITIC, IT-4F or Y6), simple colour-tuneable solar cells in which the transmission spectrum is determined solely by the choice of the organic semiconductor can be fabricated. Using a joint electrical-optical model, we show that it is possible to combine the unique attributes of high photovoltage and colour tunability to use these heterojunctions as photovoltaic windows in tandem photoelectrochemical (PEC) -photovoltaic (PV) cells. We demonstrate that this configuration can lead to a reduction in the parasitic absorption losses in the PEC-PV and thus to solar-to-hydrogen efficiencies (>3%) that are higher than that predicted using the traditionally used architecture in which the PV is placed behind the PEC.
{"title":"Colour-Tuneable Hybrid Heterojunctions as Semi-Transparent Photovoltaic Windows for Photoelectrochemical Water-Splitting","authors":"Flurin D. Eisner, B. Tam, Jun Yan, V. Belova, Wesley Ow, Mohammed Azzouzi, A. Kafizas, M. C. Quiles, A. Hankin, J. Nelson","doi":"10.2139/ssrn.3932605","DOIUrl":"https://doi.org/10.2139/ssrn.3932605","url":null,"abstract":"The strong but narrow-bandwidth absorption spectra of organic semiconductors make them excellent candidates for semi-transparent solar-cell applications in which colour-specificity is important. In this mainly theoretical study, we show that using a hybrid heterojunction combining the transparent inorganic semiconductor CuSCN with organic semiconductors (C70, PC70BM, C60, ITIC, IT-4F or Y6), simple colour-tuneable solar cells in which the transmission spectrum is determined solely by the choice of the organic semiconductor can be fabricated. Using a joint electrical-optical model, we show that it is possible to combine the unique attributes of high photovoltage and colour tunability to use these heterojunctions as photovoltaic windows in tandem photoelectrochemical (PEC) -photovoltaic (PV) cells. We demonstrate that this configuration can lead to a reduction in the parasitic absorption losses in the PEC-PV and thus to solar-to-hydrogen efficiencies (>3%) that are higher than that predicted using the traditionally used architecture in which the PV is placed behind the PEC.","PeriodicalId":10639,"journal":{"name":"Computational Materials Science eJournal","volume":"342 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77055844","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}
Yu Cai, Hongfu Zhu, Qiwu Shi, Ye Cheng, Lei Chang, Wanxia Huang
Dynamic tuning of terahertz (THz) wave is vital for the development of next generation THz devices. Utilization of solar energy for tuning THz waves is a promising, eco-friendly, and sustainable way to solve the long-standing energy crisis. Ti 2 O 3 with an ultra-narrow bandgap of 0.1eV exhibits intriguing thermal-induced metal-insulator transition(MIT), and possesses excellent photothermal conversion efficiency. Herein, Ti 2 O 3 film was fabricated by a two-step magnetron sputtering method, and exhibited excellent photothermal conversion efficiency of 90.45% and demonstrated temperature-dependent THz transmission characteristics with a wide-band at 0.1-1 THz. We supposed to combine photothermal conversion characteristics with temperature-dependent THz transmission properties of Ti 2 O 3 film, which could introduce solar light as the energy source for tuning THz waves. Our work will provide new sight for investigating MIT characteristics of Ti 2 O 3 at THz regime and exhibit huge potential in the application of tuning terahertz waves in outdoor scenarios in the future.
{"title":"Excellent Photothermal Conversion of Ti 2O 3 Film for Tuning Terahertz Waves","authors":"Yu Cai, Hongfu Zhu, Qiwu Shi, Ye Cheng, Lei Chang, Wanxia Huang","doi":"10.2139/ssrn.3942848","DOIUrl":"https://doi.org/10.2139/ssrn.3942848","url":null,"abstract":"Dynamic tuning of terahertz (THz) wave is vital for the development of next generation THz devices. Utilization of solar energy for tuning THz waves is a promising, eco-friendly, and sustainable way to solve the long-standing energy crisis. Ti 2 O 3 with an ultra-narrow bandgap of 0.1eV exhibits intriguing thermal-induced metal-insulator transition(MIT), and possesses excellent photothermal conversion efficiency. Herein, Ti 2 O 3 film was fabricated by a two-step magnetron sputtering method, and exhibited excellent photothermal conversion efficiency of 90.45% and demonstrated temperature-dependent THz transmission characteristics with a wide-band at 0.1-1 THz. We supposed to combine photothermal conversion characteristics with temperature-dependent THz transmission properties of Ti 2 O 3 film, which could introduce solar light as the energy source for tuning THz waves. Our work will provide new sight for investigating MIT characteristics of Ti 2 O 3 at THz regime and exhibit huge potential in the application of tuning terahertz waves in outdoor scenarios in the future.","PeriodicalId":10639,"journal":{"name":"Computational Materials Science eJournal","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85539972","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}
In the modern technology based society, attraction towards the redox capacitors is increasing rapidly as one of the best energy storage devices. Capacitors fabricated by using the ionic liquid (IL) based gel polymer electrolytes (GPEs) have been attracted tremendously as eco-friendly energy sources based on their unique features such as satisfactory specific capacitance, good cycle ability, and good stability. The present study reports about a redox capacitor fabricated with the IL, 1-ethyl-3-methylimidazoliumbis(trifluoromethanesulfonyl) imide (1E3Mbis(TF)I) and sodium trifluoromethanesulfonate (CF 3 NaO 3 S - NaTF). Reported highest room temperature conductivity was 7.7 x 10 -4 S cm -1 with the composition of 1 polyvinyl chloride (PVC): 1 1E3MIbis(TF)I: 2 NaTF. The conductivity mechanism of GPEs follows free volume theory. The redox capacitor with the configuration, polypyrrole (PPy): NaTF / 1 PVC: 1 1E3MIbis(TF)I: 2 NaTF / PPy: NaTF showed a single electrode specific capacitance (C SC ) of 31.5 F g -1 based on Nyquist plot. Its relaxation time was 13.6 s and this confirms fairly fast charge storage process. Initial C SC of the redox capacitor was about 126.3 F g -1 for the potential window from -1.2 V to 1.2 V. Initial single electrode discharge capacitance (C sd ) observed by Full words Galvanostatic charge discharge (GCD) test under a constant current of 240 μA was 24.1 F g -1 . It was gradually decreased to 9.57 F g -1 with cycling due to the formation of a passivation layer on the electrode and the degradation of electrolyte/electrode interface.
在以技术为基础的现代社会，氧化还原电容器作为最好的储能装置之一，其吸引力日益增加。基于离子液体凝胶聚合物电解质(GPEs)的电容器由于具有良好的比电容、良好的循环能力和良好的稳定性等特点，作为一种环保能源受到了广泛的关注。本文报道了用IL、1-乙基-3-甲基咪唑(三氟甲烷磺酰基)亚胺(1E3Mbis(TF)I)和三氟甲烷磺酸钠(cf3nao3s - NaTF)制备氧化还原电容器。报道的最高室温电导率为7.7 × 10 -4 S cm -1，组成为1聚氯乙烯(PVC): 1 1E3MIbis(TF): 2 NaTF。gpe的导电机理遵循自由体积理论。根据Nyquist图，聚吡啶(PPy): NaTF / 1 PVC: 1 1E3MIbis(TF)I: 2 NaTF / PPy: NaTF结构的氧化还原电容器的单电极比电容(SC)为31.5 F g -1。它的弛豫时间为13.6 s，这证实了电荷存储过程相当快。在-1.2 V至1.2 V的电位窗口内，氧化还原电容器的初始C - SC约为126.3℉-1。在240 μA恒流充电放电(GCD)试验条件下，观察到的初始单电极放电电容(csd)为24.1 F g -1。随着循环的进行，由于电极表面钝化层的形成和电解质/电极界面的降解，该系数逐渐降低到9.57 F g -1。
{"title":"Performance of a Na Based Ionic Liquid Based Gel Polymer Electrolyte in a Redox Capacitor","authors":"K. W. Prasadini, K. Perera, K. Vidanapathirana","doi":"10.2139/ssrn.3864800","DOIUrl":"https://doi.org/10.2139/ssrn.3864800","url":null,"abstract":"In the modern technology based society, attraction towards the redox capacitors is increasing rapidly as one of the best energy storage devices. Capacitors fabricated by using the ionic liquid (IL) based gel polymer electrolytes (GPEs) have been attracted tremendously as eco-friendly energy sources based on their unique features such as satisfactory specific capacitance, good cycle ability, and good stability. The present study reports about a redox capacitor fabricated with the IL, 1-ethyl-3-methylimidazoliumbis(trifluoromethanesulfonyl) imide (1E3Mbis(TF)I) and sodium trifluoromethanesulfonate (CF 3 NaO 3 S - NaTF). Reported highest room temperature conductivity was 7.7 x 10 -4 S cm -1 with the composition of 1 polyvinyl chloride (PVC): 1 1E3MIbis(TF)I: 2 NaTF. The conductivity mechanism of GPEs follows free volume theory. The redox capacitor with the configuration, polypyrrole (PPy): NaTF / 1 PVC: 1 1E3MIbis(TF)I: 2 NaTF / PPy: NaTF showed a single electrode specific capacitance (C SC ) of 31.5 F g -1 based on Nyquist plot. Its relaxation time was 13.6 s and this confirms fairly fast charge storage process. Initial C SC of the redox capacitor was about 126.3 F g -1 for the potential window from -1.2 V to 1.2 V. Initial single electrode discharge capacitance (C sd ) observed by Full words Galvanostatic charge discharge (GCD) test under a constant current of 240 μA was 24.1 F g -1 . It was gradually decreased to 9.57 F g -1 with cycling due to the formation of a passivation layer on the electrode and the degradation of electrolyte/electrode interface.","PeriodicalId":10639,"journal":{"name":"Computational Materials Science eJournal","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80276969","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}
Yuxuan Chen, A. Li, Zhiyuan Ma, Hui Zhang, D. Jiang, Yang Ren, L. Cui
This study presents a strategy to achieve strength-ductility synergy by introducing huge Lüders-type deformation in ultrafine grained alloys. The Lüders-type deformation occurs at a temperature range when the critical stress of deformation twinning is close to that of dislocation slip, which allows the mutual promotion between deformation twinning and dislocation slip and thus induces the band formation. The strategy was verified in a NiTiNbFe alloy which exhibited a ~50% Lüders-type strain and 1090 MPa strength when deformed at -50 ℃. This property is superb than those deformed at other temperatures.
{"title":"Achieving Strength-Ductility Synergy via Huge Lüders-Type Deformation","authors":"Yuxuan Chen, A. Li, Zhiyuan Ma, Hui Zhang, D. Jiang, Yang Ren, L. Cui","doi":"10.2139/ssrn.3834116","DOIUrl":"https://doi.org/10.2139/ssrn.3834116","url":null,"abstract":"This study presents a strategy to achieve strength-ductility synergy by introducing huge Lüders-type deformation in ultrafine grained alloys. The Lüders-type deformation occurs at a temperature range when the critical stress of deformation twinning is close to that of dislocation slip, which allows the mutual promotion between deformation twinning and dislocation slip and thus induces the band formation. The strategy was verified in a NiTiNbFe alloy which exhibited a ~50% Lüders-type strain and 1090 MPa strength when deformed at -50 ℃. This property is superb than those deformed at other temperatures.","PeriodicalId":10639,"journal":{"name":"Computational Materials Science eJournal","volume":"119 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78636378","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：