Journal of Physics: Materials最新文献

Electronic transport in reactively sputtered Mn3GaN films prepared under optimized nitrogen flow 在优化氮气流条件下制备的反应溅射 Mn3GaN 薄膜中的电子传输

Journal of Physics: Materials Pub Date : 2024-08-29 DOI: 10.1088/2515-7639/ad71f5

Christoph Sürgers, Gerda Fischer, Sihao Deng, Dongmei Hu, Cong Wang

{"title":"Electronic transport in reactively sputtered Mn3GaN films prepared under optimized nitrogen flow","authors":"Christoph Sürgers, Gerda Fischer, Sihao Deng, Dongmei Hu, Cong Wang","doi":"10.1088/2515-7639/ad71f5","DOIUrl":"https://doi.org/10.1088/2515-7639/ad71f5","url":null,"abstract":"Mn-based nitrides with antiperovskite structures have several properties that can be utilized for antiferromagnetic spintronics. Their magnetic properties depend on the structural quality, composition and doping of the cubic antiperovskite structure. Such nitride thin films are usually produced by reactive physical vapor deposition, where the deposition rate of N can only be controlled by the N2 gas flow. We show that the tuning of the N content can be optimized using low temperature resistivity measurements, which serve as an indicator of the degree of structural disorder. Several Mn3GaN<italic toggle=\"yes\">x</italic> films were prepared by reactive magnetron sputtering under different N2 gas flows. Under optimized gas flow conditions, we obtain films that exhibit a metal-like temperature dependence of the resistivity, a vanishing logarithmic increase of the resistivity towards zero, the highest resistivity ratio, and a lattice contraction of 0.4% along the growth direction when heated above the Néel temperature <inline-formula>\u0000<tex-math><?CDATA $T_textrm{N}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msub><mml:mi>T</mml:mi><mml:mtext>N</mml:mtext></mml:msub></mml:mrow></mml:math><inline-graphic xlink:href=\"jpmaterad71f5ieqn1.gif\"></inline-graphic></inline-formula>. The retarded formation of an additional magnetic phase appearing at a temperature <inline-formula>\u0000<tex-math><?CDATA $T^{ast} ll T_textrm{N}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msup><mml:mi>T</mml:mi><mml:mrow><mml:mo>∗</mml:mo></mml:mrow></mml:msup><mml:mo>≪</mml:mo><mml:msub><mml:mi>T</mml:mi><mml:mtext>N</mml:mtext></mml:msub></mml:mrow></mml:math><inline-graphic xlink:href=\"jpmaterad71f5ieqn2.gif\"></inline-graphic></inline-formula> gives rise to a large thermal hysteresis of the resistivity and anomalous Hall effect.","PeriodicalId":501825,"journal":{"name":"Journal of Physics: Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178185","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}

引用次数: 0

Correlation between optical phonon softening and superconducting Tc in YBa2Cu3Ox within d-wave Eliashberg theory d 波埃利亚斯伯格理论中 YBa2Cu3Ox 的光学声子软化与超导 Tc 之间的相关性

Journal of Physics: Materials Pub Date : 2024-08-14 DOI: 10.1088/2515-7639/ad6c7f

Cunyuan Jiang, Giovanni Alberto Ummarino, Matteo Baggioli, Efthymios Liarokapis, Alessio Zaccone

{"title":"Correlation between optical phonon softening and superconducting Tc in YBa2Cu3Ox within d-wave Eliashberg theory","authors":"Cunyuan Jiang, Giovanni Alberto Ummarino, Matteo Baggioli, Efthymios Liarokapis, Alessio Zaccone","doi":"10.1088/2515-7639/ad6c7f","DOIUrl":"https://doi.org/10.1088/2515-7639/ad6c7f","url":null,"abstract":"We provide a mathematical description, based on <italic toggle=\"yes\">d</italic>-wave Eliashberg theory, of the strong correlation between the experimentally observed softening of Raman modes associated with in-plane oxygen motions and the corresponding superconducting critical temperature <inline-formula>\u0000<tex-math><?CDATA $T_mathrm{c}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msub><mml:mi>T</mml:mi><mml:mrow><mml:mi mathvariant=\"normal\">c</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math><inline-graphic xlink:href=\"jpmaterad6c7fieqn2.gif\"></inline-graphic></inline-formula>, as a function of oxygen doping <italic toggle=\"yes\">x</italic>, in YBa2Cu3O<italic toggle=\"yes\">x</italic>. The theoretical model provides a direct link between physical trends of soft optical <italic toggle=\"yes\">Ag</italic> (in-plane) oxygen modes, the level of oxygen doping <italic toggle=\"yes\">x</italic>, and the superconducting <inline-formula>\u0000<tex-math><?CDATA $T_mathrm{c}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msub><mml:mi>T</mml:mi><mml:mrow><mml:mi mathvariant=\"normal\">c</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math><inline-graphic xlink:href=\"jpmaterad6c7fieqn3.gif\"></inline-graphic></inline-formula>. Different regimes observed in the trend of <inline-formula>\u0000<tex-math><?CDATA $T_mathrm{c}$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msub><mml:mi>T</mml:mi><mml:mrow><mml:mi mathvariant=\"normal\">c</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math><inline-graphic xlink:href=\"jpmaterad6c7fieqn4.gif\"></inline-graphic></inline-formula> vs doping can be related to corresponding regimes of optical phonon softening in the Raman spectra. These results provide further evidence related to the physical origin of high-temperature superconductivity in rare-earth cuprate oxides and to the significant role of electron–phonon coupling therein.","PeriodicalId":501825,"journal":{"name":"Journal of Physics: Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178190","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}

引用次数: 0

Tribological manufacturing of ZDDP tribofilms functionalised by graphene nanoplatelets 石墨烯纳米片功能化 ZDDP 三膜的摩擦学制造

Journal of Physics: Materials Pub Date : 2024-08-11 DOI: 10.1088/2515-7639/ad6930

S Duston, R A Oliver, K J Kubiak, Y Wang, C Wang and A Morina

{"title":"Tribological manufacturing of ZDDP tribofilms functionalised by graphene nanoplatelets","authors":"S Duston, R A Oliver, K J Kubiak, Y Wang, C Wang and A Morina","doi":"10.1088/2515-7639/ad6930","DOIUrl":"https://doi.org/10.1088/2515-7639/ad6930","url":null,"abstract":"3D Tribo-Nanoprinting (3D TNP), which uses a highly controllable tribological contact to deposit tribofilms, has been proposed as a manufacturing method for nanoscale structures. Inspired by this, we show for the first time, as a proof of concept, the ability to electrically functionalise tribofilms for potential use in the manufacture of structures with nanoscale thickness. Zinc dialkyldithiophosphate (ZDDP) tribofilms have been generated to include varying concentrations of graphene nanoplatelets (GNPs) resulting in them becoming electrically conductive when tested using conductive atomic force microscopy. In its highest GNP concentration, approximately 55% of the surface of the tribofilm was able to sustain current up to a threshold of 245 pA. The higher graphene content led to a suppression in film formation and decreased substrate coverage. Transmission electron microscopy revealed a dual-layered tribofilm with a carbon-rich layer above a pure layer of ZDDP tribofilm. Within the carbon-rich layer, the GNPs formed into scrolls which created an internal network through which current could flow, being limited by the insulating pure ZDDP layer at the film-substrate interface, and the presence of surface graphene sheets. A modified lateral force microscopy procedure supported the presence of surface graphene sheets. Despite limited deposition precision in terms of homogeneity and distribution of the tribofilms, this work provides a step towards the use of 3D TNP for the manufacture of electronic structures on the nanoscale by proving that tribofilms can be functionalised by the addition of particle additives.","PeriodicalId":501825,"journal":{"name":"Journal of Physics: Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141936264","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}

引用次数: 0

Insights about the effect of metal-organic framework hybridization with graphene-like materials 金属有机框架与类石墨烯材料杂化效应的启示

Journal of Physics: Materials Pub Date : 2024-08-08 DOI: 10.1088/2515-7639/ad6cf6

V. Gargiulo, Roberto Di Capua, M. Vorochta, G. Aquilanti, Tomáš Skála, Claudio Clemente, M. Alfè

引用次数: 0

Mesoscale modeling of random chain scission in polyethylene melts 聚乙烯熔体中无规链裂解的中尺度建模

Journal of Physics: Materials Pub Date : 2024-07-18 DOI: 10.1088/2515-7639/ad5c06

Arefin Mustafa Anik, Vaibhav Palkar, Igor Luzinov and Olga Kuksenok

{"title":"Mesoscale modeling of random chain scission in polyethylene melts","authors":"Arefin Mustafa Anik, Vaibhav Palkar, Igor Luzinov and Olga Kuksenok","doi":"10.1088/2515-7639/ad5c06","DOIUrl":"https://doi.org/10.1088/2515-7639/ad5c06","url":null,"abstract":"Polyolefins account for more than half of global primary polymer production, however only a small fraction of these polymers are currently being recycled. Fragmentation of polymer chains into shorter chains with a targeted molecular weight distribution with the goal of reusing these fragments in subsequent chemical synthesis can potentially introduce an alternative approach to polyolefins recycling. Herein we develop a mesoscale framework to model degradation of polyethylene melts at a range of high temperatures. We use the dissipative particle dynamics approach with modified segmental repulsive potential to model the process of random scission in melts of linear polymer chains. We characterize the fragmentation process by tracking the time evolution of the distribution of degrees of polymerization of chain fragments. Specifically, we track the weight average and the number average degrees of polymerization and dispersity of polymer fragments as a function of the fraction of bonds broken. Furthermore, we track the number fraction distribution and the weight fraction distribution of polymer fragments with various degrees of polymerization as functions of the fraction of bonds broken for a range of high temperatures. Our results allow one to quantify to what extent the distribution of polymer chain fragments during random scission can be captured by the respective analytical distributions for the range of conversions considered. Understanding the thermal degradation of polyolefins on the mesoscale can result in the development of alternative strategies for recycling a range of thermoplastics.","PeriodicalId":501825,"journal":{"name":"Journal of Physics: Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141741508","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}

引用次数: 0

Characteristic features of strong correlation: lessons from a 3-fermionone-dimensional harmonic trap 强相关性的特征：3-费米子一维谐波陷阱的启示

Journal of Physics: Materials Pub Date : 2024-07-16 DOI: 10.1088/2515-7639/ad63cb

Victor Caliva, J. I. Fuks

{"title":"Characteristic features of strong correlation: lessons from a 3-fermionone-dimensional harmonic trap","authors":"Victor Caliva, J. I. Fuks","doi":"10.1088/2515-7639/ad63cb","DOIUrl":"https://doi.org/10.1088/2515-7639/ad63cb","url":null,"abstract":"\u0000 Many quantum phenomena responsible for key applications in material science and quantum chemistry arise in the strongly correlated regime. This is at the same time, a costly regime for computer simulations. In the limit of strong correlation analytic solutions exist, but as we move away from this limit numerical simulation are needed, and accurate quantum solutions do not scale well with the number of interacting particles. In this work we propose to use few-particle harmonic traps in combination with twisted light as a quantum emulator to investigate the transition into a strongly-correlated regime. Using both analytic derivations and numerical simulations we generalize previous findings on 2 Coulomb interacting fermions trapped in a one-dimensional harmonic trap to the case of 3 fermions. The 4 signatures of strong correlation we have identified in the one- dimensional harmonic trap are: i) the ground state density is highly localized around N equilibrium positions, where N is the number of particles, ii) the symmetric and antisymmetric ground state wavefunctions become degenerate, iii) the von Neumann entropy grows, iv) the energy spectrum is fully characterized by N normal modes or less. Our findings describe the low-energy behavior of electrons in quantum wires and ions in Paul traps. Similar features have also been reported for cold atoms in optical lattices.","PeriodicalId":501825,"journal":{"name":"Journal of Physics: Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141641281","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}

引用次数: 0

Effects of bubble-induced strain on the magnetic properties of van der Waals ferromagnet CrBr3 气泡诱导应变对范德华铁磁体 CrBr3 磁性能的影响

Journal of Physics: Materials Pub Date : 2024-07-11 DOI: 10.1088/2515-7639/ad5ec1

Sergey Grebenchuk, Magdalena Grzeszczyk, Zhaolong Chen, Kostya S Novoselov and Maciej Koperski

引用次数: 0

Indirect magneto-ionic effect in FeSi2/Si nanocomposite induced by electrochemical lithiation and delithiation 电化学石化和脱石化诱导的 FeSi2/Si 纳米复合材料中的间接磁离子效应

Journal of Physics: Materials Pub Date : 2024-07-10 DOI: 10.1088/2515-7639/ad618e

Matthias Prasch, Roland Wuerschum, S. Topolovec

{"title":"Indirect magneto-ionic effect in FeSi2/Si nanocomposite induced by electrochemical lithiation and delithiation","authors":"Matthias Prasch, Roland Wuerschum, S. Topolovec","doi":"10.1088/2515-7639/ad618e","DOIUrl":"https://doi.org/10.1088/2515-7639/ad618e","url":null,"abstract":"\u0000 A nanocomposite consisting of iron disilicide nanocrystals embedded in a Si matrix was prepared from industry-grade ferrosilicon by ball milling and subsequent heat treatment. By tailoring the heat treatment temperature either the metallic α-FeSi2 or the semiconducting β-FeSi2 phase could be made the dominant one, as indicated by X-ray diffraction. Magnetization curve and zero-field cooled/field cooled measurements revealed that ferromagnetic and superparamagnetic centers are present in the nanocomposites, which could be attributed to Fe-rich defective regions at the surface of the iron disilicide nanocrystals. For both nanocomposites, containing either mainly the α or β phase, we could show that the magnetization can be varied by about 40% by electrochemical lithiation and delithiation of the surrounding Si matrix, with up to 6.5% of the magnetization change beingreversible. These variations could be attributed to the formation of additional Fe-rich magnetic regions, induced by a local change of the Fe/Si fraction at the FeSi2/Si interfaces, and their subsequent partial elimination. Thus, this work demonstrates a new concept for how an \"indirect magneto-ionic effect'' can be obtained in composite materials consisting of a phase prone to the electrochemical ion uptake (i.e., the Si matrix) and a magnetic phase (i.e., the FeSi2 nanocrystals).","PeriodicalId":501825,"journal":{"name":"Journal of Physics: Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141660843","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}

引用次数: 0

An analytical-atomistic model for elastic behavior of silicon nanowires 硅纳米线弹性行为的分析原子模型

Journal of Physics: Materials Pub Date : 2024-07-10 DOI: 10.1088/2515-7639/ad618d

Sina Zare Pakzad, M. Nasr Esfahani, B. E. Alaca

引用次数: 0

Acoustically transparent alumina-based cranial implants enhance ultrasound transmission through a combined mechano-acoustic resonant effect 声学透明氧化铝颅骨植入物通过机械-声学共振组合效应增强超声波传输能力

Journal of Physics: Materials Pub Date : 2024-07-03 DOI: 10.1088/2515-7639/ad5c05

Mario Ibrahin Gutierrez, Pathikumar Sellappan, Elias H Penilla, Irais Poblete-Naredo, Arturo Vera, Lorenzo Leija and Javier E Garay

{"title":"Acoustically transparent alumina-based cranial implants enhance ultrasound transmission through a combined mechano-acoustic resonant effect","authors":"Mario Ibrahin Gutierrez, Pathikumar Sellappan, Elias H Penilla, Irais Poblete-Naredo, Arturo Vera, Lorenzo Leija and Javier E Garay","doi":"10.1088/2515-7639/ad5c05","DOIUrl":"https://doi.org/10.1088/2515-7639/ad5c05","url":null,"abstract":"Therapeutic ultrasound for brain stimulation has increased in the last years. This energy has shown promising results for treating Alzheimer’s disease, Parkinson’s disease and traumatic brain injury, among other conditions. However, the application of ultrasound in the brain should trespass a natural but highly attenuating and distorting barrier, the cranium. Implantable ceramic materials can be used to replace part of the cranium as an alternate method to enhance ultrasound transmission. In this work, it is presented the acoustic characterization of alumina ceramic disks that can be employed as cranial implants for acoustic windows-to-the-brain. Alumina samples were prepared using current-activated pressure-assisted densification and were acoustically characterized. Acoustic impedance and attenuation of the samples were determined for different porosities. Additionally, measured and modeled acoustic fields are presented and analyzed in terms of the total ultrasound transmitted through the ceramics. Results indicate a resonant behavior in the alumina disks when the thickness corresponds to a half-wavelength of ultrasound; this resonance permits a total of 95.4% of ultrasound transmission; for thicknesses out of the resonant zone, transmission is 53.0%. Alumina proves to be an excellent medium for ultrasound transmission that, in conjunction with its mechanical and optical properties, can be useful for cranium replacement in mixed opto-acoustic applications.","PeriodicalId":501825,"journal":{"name":"Journal of Physics: Materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141550884","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}

引用次数: 0