Mohamed S. Abdo, Muhammad A. Shar, Ahmed Fouly, Mushtaq A. Dar, Hany S. Abdo
This study investigates the enhancement of mechanical and tribological behavior in polymethyl methacrylate (PMMA) composites reinforced with graphene oxide (GO) as a solid lubricant filler for advanced biomedical applications, particularly dental implants. PMMA/GO composites were prepared with varying weight percentages of GO (0, 0.2, 0.5, 0.7, and 1 wt. %) to assess their impact on material performance. A noteworthy improvement in both tensile strength and Young’s modulus was detected, reaching up to 141% and 10.6%, respectively, at optimized GO loadings of 1%. Microstructural analysis utilizing scanning electron microscopy for the worn surface revealed enhanced dispersion and interfacial adhesion between GO and the PMMA matrix, reinforcing mechanical coherence. Tribological properties also demonstrated enhancement, with PMMA composites containing 1 wt. % GO exhibiting optimal mechanical and tribological characteristics compared to lower weight fractions. Moreover, microscopic examination revealed a shift in the wear mechanism of the PMMA-GO composite, which was attributed to the lower friction coefficient obtained by GO integration.
本研究探讨了用氧化石墨烯（GO）作为固体润滑剂填料增强聚甲基丙烯酸甲酯（PMMA）复合材料的机械和摩擦学性能，用于先进的生物医学应用，尤其是牙科植入物。我们制备了不同重量百分比（0、0.2、0.5、0.7 和 1 重量百分比）的 PMMA/GO 复合材料，以评估它们对材料性能的影响。拉伸强度和杨氏模量均有显著提高，在 GO 的优化负载量为 1%时，拉伸强度和杨氏模量分别提高了 141% 和 10.6%。利用扫描电子显微镜对磨损表面进行的微观结构分析表明，GO 和 PMMA 基体之间的分散性和界面粘附性得到了增强，从而加强了机械一致性。摩擦学特性也得到了增强，与较低重量分数相比，含有 1 重量百分比 GO 的 PMMA 复合材料表现出最佳的机械和摩擦学特性。此外，显微镜检查显示，PMMA-GO 复合材料的磨损机制发生了变化，这归因于 GO 集成降低了摩擦系数。
{"title":"Experimental investigation on the tribo-mechanical behavior of PMMA reinforced by solid lubricant filler for dental implant applications","authors":"Mohamed S. Abdo, Muhammad A. Shar, Ahmed Fouly, Mushtaq A. Dar, Hany S. Abdo","doi":"10.1063/5.0225107","DOIUrl":"https://doi.org/10.1063/5.0225107","url":null,"abstract":"This study investigates the enhancement of mechanical and tribological behavior in polymethyl methacrylate (PMMA) composites reinforced with graphene oxide (GO) as a solid lubricant filler for advanced biomedical applications, particularly dental implants. PMMA/GO composites were prepared with varying weight percentages of GO (0, 0.2, 0.5, 0.7, and 1 wt. %) to assess their impact on material performance. A noteworthy improvement in both tensile strength and Young’s modulus was detected, reaching up to 141% and 10.6%, respectively, at optimized GO loadings of 1%. Microstructural analysis utilizing scanning electron microscopy for the worn surface revealed enhanced dispersion and interfacial adhesion between GO and the PMMA matrix, reinforcing mechanical coherence. Tribological properties also demonstrated enhancement, with PMMA composites containing 1 wt. % GO exhibiting optimal mechanical and tribological characteristics compared to lower weight fractions. Moreover, microscopic examination revealed a shift in the wear mechanism of the PMMA-GO composite, which was attributed to the lower friction coefficient obtained by GO integration.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"7 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142185401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have theoretically and experimentally demonstrated the feasibility of achieving ultra-low dark current in CpBnn type detectors based on a double-barrier InAs/GaSb/AlSb type-II superlattice. By employing a structure that separates the absorption region and depletion region, the diffusion, recombination, tunneling, and surface dark currents of the photodetector (PD) have been suppressed. Experimental validation has shown that a detector with a diameter of 500 µm at a bias voltage of −0.5 V exhibits a dark current density of 2.5 × 10−6 A/cm2 at the operating temperature of 300 K. The development of PD with low dark current has paved the way for applications with high demands for low noise in the fields of gravitational wave detection and astronomical observation.
我们从理论和实验上证明了在基于 InAs/GaSb/AlSb II 型双势垒超晶格的 CpBnn 型探测器中实现超低暗电流的可行性。通过采用吸收区和耗尽区分离的结构，光电探测器（PD）的扩散、重组、隧道和表面暗电流都得到了抑制。实验验证表明，直径为 500 微米的探测器在-0.5 V 的偏置电压下，工作温度为 300 K 时的暗电流密度为 2.5 × 10-6 A/cm2。
{"title":"Low dark current Sb-based short-wavelength infrared photodetector","authors":"Mingming Li, Yifan Cheng, Xiangyu Zhang, Ye Zhang, Dongwei Jiang, Zhigang Song, Wanhua Zheng","doi":"10.1063/5.0207138","DOIUrl":"https://doi.org/10.1063/5.0207138","url":null,"abstract":"We have theoretically and experimentally demonstrated the feasibility of achieving ultra-low dark current in CpBnn type detectors based on a double-barrier InAs/GaSb/AlSb type-II superlattice. By employing a structure that separates the absorption region and depletion region, the diffusion, recombination, tunneling, and surface dark currents of the photodetector (PD) have been suppressed. Experimental validation has shown that a detector with a diameter of 500 µm at a bias voltage of −0.5 V exhibits a dark current density of 2.5 × 10−6 A/cm2 at the operating temperature of 300 K. The development of PD with low dark current has paved the way for applications with high demands for low noise in the fields of gravitational wave detection and astronomical observation.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"6 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To address the dual problems of fuel reliance and air pollution, this study describes the design of a wireless ground to vehicle charging system powered by solar energy and specifically designed for electric vehicle (EV) charging stations. As the number of electric vehicles on the road steadily rises, they present a viable way to cut travel expenses by switching from conventional fuel to electricity, which is a more economical and sustainable option. With the introduction of a wireless EV charging system, this creative solution does away with the need for external power sources and permits continuous charging without interfering with driving. Utilizing solar power, the charging system incorporates solar panels, batteries, circuit regulators, boost converters, receiver and transmitter copper coils, AC/DC converters, microcontrollers (such as ATmega), LCD screens, and circuit regulators. This study describes a technique that shows that charging electric cars while driving is feasible and eliminates the need to stop. This technology for wireless solar electric vehicle charging presents a forward-thinking approach to sustainable mobility by providing a workable solution that can be easily included in the road infrastructure. For the wireless charging, in addition, various coil designs are suggested.
{"title":"Design of wireless charging system for E-Vehicle","authors":"Shweta L. Tiwari, S. R. Gaigowal, Kiran Raut","doi":"10.1063/5.0218429","DOIUrl":"https://doi.org/10.1063/5.0218429","url":null,"abstract":"To address the dual problems of fuel reliance and air pollution, this study describes the design of a wireless ground to vehicle charging system powered by solar energy and specifically designed for electric vehicle (EV) charging stations. As the number of electric vehicles on the road steadily rises, they present a viable way to cut travel expenses by switching from conventional fuel to electricity, which is a more economical and sustainable option. With the introduction of a wireless EV charging system, this creative solution does away with the need for external power sources and permits continuous charging without interfering with driving. Utilizing solar power, the charging system incorporates solar panels, batteries, circuit regulators, boost converters, receiver and transmitter copper coils, AC/DC converters, microcontrollers (such as ATmega), LCD screens, and circuit regulators. This study describes a technique that shows that charging electric cars while driving is feasible and eliminates the need to stop. This technology for wireless solar electric vehicle charging presents a forward-thinking approach to sustainable mobility by providing a workable solution that can be easily included in the road infrastructure. For the wireless charging, in addition, various coil designs are suggested.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"53 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142185399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiangyu Xu, Xigui Tao, Yingxiang Wu, Yunke Lu, Yan Liu, Ji Zhang, Yushuai Zhang
The projectile deflects and even ricochets after an oblique impact on the concrete. However, research on the oblique impact of projectiles on concrete targets mainly focuses on oblique penetration and the critical ricochet angle, and there are few experimental studies on ricochets. Deflection and its influencing factors remain undefined. This study conducted experiments and LS-DYNA numerical simulations on projectiles obliquely impacting C60 concrete targets. The experimental research visually revealed deflection and ricochet phenomena after the oblique impact. The ricochet caused by large-angle impacts can effectively reduce the damaged area of concrete targets. Subsequently, the main governing parameters affecting the deflection angle of the projectile were identified through dimensional analysis, and a sensitivity analysis was performed on these parameters using an orthogonal experimental design. On this basis, the influence of the incident angle, impact velocity, and projectile length-to-diameter ratio on the projectile deflection was further clarified. The results showed that the maximum deflection angle was achieved when a 30 mm caliber projectile obliquely impacted a C60 concrete at an incident angle of ∼45°. In the case of ricochets, the deflection angle increased with an increase in the impact velocity and decreased with an increase in the length-to-diameter ratio. This study aids in predicting and controlling projectile deflection and provides a reference for the innovative design of concrete protective structures.
{"title":"Deflection characteristics and influencing factors of projectile oblique impact on concrete targets","authors":"Xiangyu Xu, Xigui Tao, Yingxiang Wu, Yunke Lu, Yan Liu, Ji Zhang, Yushuai Zhang","doi":"10.1063/5.0220438","DOIUrl":"https://doi.org/10.1063/5.0220438","url":null,"abstract":"The projectile deflects and even ricochets after an oblique impact on the concrete. However, research on the oblique impact of projectiles on concrete targets mainly focuses on oblique penetration and the critical ricochet angle, and there are few experimental studies on ricochets. Deflection and its influencing factors remain undefined. This study conducted experiments and LS-DYNA numerical simulations on projectiles obliquely impacting C60 concrete targets. The experimental research visually revealed deflection and ricochet phenomena after the oblique impact. The ricochet caused by large-angle impacts can effectively reduce the damaged area of concrete targets. Subsequently, the main governing parameters affecting the deflection angle of the projectile were identified through dimensional analysis, and a sensitivity analysis was performed on these parameters using an orthogonal experimental design. On this basis, the influence of the incident angle, impact velocity, and projectile length-to-diameter ratio on the projectile deflection was further clarified. The results showed that the maximum deflection angle was achieved when a 30 mm caliber projectile obliquely impacted a C60 concrete at an incident angle of ∼45°. In the case of ricochets, the deflection angle increased with an increase in the impact velocity and decreased with an increase in the length-to-diameter ratio. This study aids in predicting and controlling projectile deflection and provides a reference for the innovative design of concrete protective structures.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"26 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper discusses the application of reactive multiparticle collision (RMPC) dynamics, a particle-based method, to epidemic models. First, we consider a susceptible-infectious-recovered framework to obtain data on contacts of susceptibles with infectious people in a population. It is found that the number of contacts increases and the contact duration decreases with increases in the disease transmission rate and average population speed. Next, we obtain reinfection statistics for a general infectious disease from RMPC simulations of a susceptible-infectious-recovered-susceptible model. Finally, we simulate a susceptible-exposed-infectious-recovered model and gather the exposure, infection, and recovery time for the individuals in the population under consideration. It is worth mentioning that we can collect data in the form of average contact duration, average initial infection time, etc., from RMPC simulations of these models, which is not possible with population-based stochastic models, or deterministic systems. This study provides quantitative insights on the potential of RMPC to simulate epidemic models and motivates future efforts for its application in the field of mathematical epidemiology.
{"title":"On the use of reactive multiparticle collision dynamics to gather particulate level information from simulations of epidemic models","authors":"Zaib Un Nisa Memon, Katrin Rohlf","doi":"10.1063/5.0223361","DOIUrl":"https://doi.org/10.1063/5.0223361","url":null,"abstract":"This paper discusses the application of reactive multiparticle collision (RMPC) dynamics, a particle-based method, to epidemic models. First, we consider a susceptible-infectious-recovered framework to obtain data on contacts of susceptibles with infectious people in a population. It is found that the number of contacts increases and the contact duration decreases with increases in the disease transmission rate and average population speed. Next, we obtain reinfection statistics for a general infectious disease from RMPC simulations of a susceptible-infectious-recovered-susceptible model. Finally, we simulate a susceptible-exposed-infectious-recovered model and gather the exposure, infection, and recovery time for the individuals in the population under consideration. It is worth mentioning that we can collect data in the form of average contact duration, average initial infection time, etc., from RMPC simulations of these models, which is not possible with population-based stochastic models, or deterministic systems. This study provides quantitative insights on the potential of RMPC to simulate epidemic models and motivates future efforts for its application in the field of mathematical epidemiology.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"310 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Orbital currents in light metals or metal oxides without the strong spin–orbit coupling have become an important means to achieve low-power magnetization switching in spin–orbitronic devices. The orbital magnetoresistance (OMR) originated from orbital current represents a useful strategy to explore the interaction between the orbital angular momentum (OAM) and the local magnetic moment. However, systematic research works on the enhancement of OMR and the mechanism of OAM transport are seldom reported. In this study, we report a synergistically enhanced magnetoresistance effect induced by spin and orbital currents in perpendicularly magnetized Pt/Co/Cu–CuOx systems. A maximum room temperature magnetoresistance of 0.38% was observed, exceeding the spin Hall magnetoresistance (SMR) of heavy metal-based heterostructures by one order of magnitude. The enhancement of magnetoresistance is attributed to the contributions from the OMR generated by the orbital Rashba effect at the Cu/CuOx interface and SMR induced by the spin Hall effect in heavy metal Pt. These results provide a pathway to understanding of the OAM transport in magnetic multilayer films and contribute to the design and realization of energy-efficient spin–orbitronic devices.
{"title":"Enhanced magnetoresistance induced collaboratively by spin and orbital currents","authors":"Shuyi Yang, Jinnan Liu, Huan Liu, Yongji Li, Wei Zhang, Zhongming Zeng, Zhiyong Quan","doi":"10.1063/5.0231164","DOIUrl":"https://doi.org/10.1063/5.0231164","url":null,"abstract":"Orbital currents in light metals or metal oxides without the strong spin–orbit coupling have become an important means to achieve low-power magnetization switching in spin–orbitronic devices. The orbital magnetoresistance (OMR) originated from orbital current represents a useful strategy to explore the interaction between the orbital angular momentum (OAM) and the local magnetic moment. However, systematic research works on the enhancement of OMR and the mechanism of OAM transport are seldom reported. In this study, we report a synergistically enhanced magnetoresistance effect induced by spin and orbital currents in perpendicularly magnetized Pt/Co/Cu–CuOx systems. A maximum room temperature magnetoresistance of 0.38% was observed, exceeding the spin Hall magnetoresistance (SMR) of heavy metal-based heterostructures by one order of magnitude. The enhancement of magnetoresistance is attributed to the contributions from the OMR generated by the orbital Rashba effect at the Cu/CuOx interface and SMR induced by the spin Hall effect in heavy metal Pt. These results provide a pathway to understanding of the OAM transport in magnetic multilayer films and contribute to the design and realization of energy-efficient spin–orbitronic devices.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"12 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Relativistic backward wave oscillators (RBWOs) have the characteristics of high power and high repetition rate. Reducing the magnetic field strength and the weight of the external permanent magnet (PM) is a significant development direction of RBWOs. In previous research, an X-band RBWO enclosed with a PM has achieved a power efficiency of 50%. However, the PM used in these papers requires a magnetic field magnitude of over 0.68 T, which leads to a weight exceeding 400 kg. The RBWO designed in this paper operates in coaxial TM01 mode, and the radial distance between its cathode and the surface of the slow wave structures reaches 7 mm. Under the condition of a low magnetic field, this design can provide a wide electron beam channel to avoid the rubbing of the electron beam envelope on the inner and outer conductors. Particle-in-cell simulation results have demonstrated that this RBWO achieves an output microwave power of 3 GW with a power efficiency of 50% enclosed in a PM with a magnetic field strength of 0.43 T and a weight of 74 kg.
{"title":"Design of an X-band high efficiency coaxial relativistic backward wave oscillator with permanent magnetic package","authors":"Kaiqi Yang, Fugui Zhou, Dian Zhang, Zhenxing Jin, Yujie Xiang, Tengfang Wang, Wei Zhang","doi":"10.1063/5.0223711","DOIUrl":"https://doi.org/10.1063/5.0223711","url":null,"abstract":"Relativistic backward wave oscillators (RBWOs) have the characteristics of high power and high repetition rate. Reducing the magnetic field strength and the weight of the external permanent magnet (PM) is a significant development direction of RBWOs. In previous research, an X-band RBWO enclosed with a PM has achieved a power efficiency of 50%. However, the PM used in these papers requires a magnetic field magnitude of over 0.68 T, which leads to a weight exceeding 400 kg. The RBWO designed in this paper operates in coaxial TM01 mode, and the radial distance between its cathode and the surface of the slow wave structures reaches 7 mm. Under the condition of a low magnetic field, this design can provide a wide electron beam channel to avoid the rubbing of the electron beam envelope on the inner and outer conductors. Particle-in-cell simulation results have demonstrated that this RBWO achieves an output microwave power of 3 GW with a power efficiency of 50% enclosed in a PM with a magnetic field strength of 0.43 T and a weight of 74 kg.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"3 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electrons in transition metal dichalcogenides stacked on opposite sides of BN of thickness d can form solids, which have no long range position order but are characterized by a finite shear modulus. The melting temperature Tm is characterized by the occurrence of unbound quantum topological defects. Tm of this solid is four orders of magnitude larger than that of previously studied electron solids in Si-MOSFETs. As the density n = n0 × 1012/cm2 is changed so that both the top and the bottom electron densities are the same, for n0 > 1.5 with d = 5 nm, a hexagonal solid is manifested experimentally by a five order of magnitude increase in Coulomb drag resistance Rdrag at room temperature. This resistance change corresponds to a four orders of magnitude better subthreshold slope, the key parameter for semiconductor device low power switching, over existing limits for MOSFETs from “Boltzmann’s tyranny.” The symmetry of the two-layer solid can be tuned by varying the density. The hexagonal lattice becomes soft at n0 ≈ 1.5. There is a further two orders of magnitude increase in Rdrag due to an increase in disorder caused by the large quantum fluctuation of the lattice position that is of 0.4 order of the lattice spacing. The subthreshold slope is improved by two more orders of magnitude. For n0 < 1.5, different phases of the solid corresponding to peaks of Rdrag of different magnitude at different gate voltages start to form. This raises the intriguing possibility of making new classes of devices with ternary and higher order systems where the different phases correspond to different logical states and not just two states of on (low resistance) and off (high resistance).
{"title":"Symmetry change of quantum electron solids in double layer MoS2","authors":"S. T. Chui, Meizhen Huang, Zefei Wu, Ning Wang","doi":"10.1063/5.0223186","DOIUrl":"https://doi.org/10.1063/5.0223186","url":null,"abstract":"Electrons in transition metal dichalcogenides stacked on opposite sides of BN of thickness d can form solids, which have no long range position order but are characterized by a finite shear modulus. The melting temperature Tm is characterized by the occurrence of unbound quantum topological defects. Tm of this solid is four orders of magnitude larger than that of previously studied electron solids in Si-MOSFETs. As the density n = n0 × 1012/cm2 is changed so that both the top and the bottom electron densities are the same, for n0 &gt; 1.5 with d = 5 nm, a hexagonal solid is manifested experimentally by a five order of magnitude increase in Coulomb drag resistance Rdrag at room temperature. This resistance change corresponds to a four orders of magnitude better subthreshold slope, the key parameter for semiconductor device low power switching, over existing limits for MOSFETs from “Boltzmann’s tyranny.” The symmetry of the two-layer solid can be tuned by varying the density. The hexagonal lattice becomes soft at n0 ≈ 1.5. There is a further two orders of magnitude increase in Rdrag due to an increase in disorder caused by the large quantum fluctuation of the lattice position that is of 0.4 order of the lattice spacing. The subthreshold slope is improved by two more orders of magnitude. For n0 &lt; 1.5, different phases of the solid corresponding to peaks of Rdrag of different magnitude at different gate voltages start to form. This raises the intriguing possibility of making new classes of devices with ternary and higher order systems where the different phases correspond to different logical states and not just two states of on (low resistance) and off (high resistance).","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"41 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Kunc, T. Fridrišek, M. Shestopalov, J. Jo, K. Park
We studied the transport properties of graphene–insulator–metal tunneling diodes. Two sets of tunneling diodes with Ti–Cu and Cr–Au top contacts are fabricated. Transport measurements showed state-of-the-art non-linearity and a critical influence of the top metals on the dielectric strength of the tunneling barrier. X-ray photoelectron spectroscopy indicated two methods for enhancing the dielectric strength of the tunneling barrier. These are the optimized seed layers for the growth of high-quality conformal insulators and the selection of appropriate top metal layers with a small diffusion coefficient and electromigration into the Al2O3 barrier. The Cr–Au top contact provides superior characteristics to the Ti–Cu metallization. X-ray photoelectron spectroscopy showed significant diffusion of titanium during the Al2O3 growth and the formation of titanium inclusions after annealing. Chromium diffusion is slower than that of titanium, making chromium contact more suitable for the reliable operation of tunneling diodes. As a result, we demonstrate a 40% improvement in the dielectric strength of the tunneling barrier compared to state-of-the-art metal–insulator–metal diodes.
{"title":"Graphene–insulator–metal diodes: Enhanced dielectric strength of the Al2O3 barrier","authors":"J. Kunc, T. Fridrišek, M. Shestopalov, J. Jo, K. Park","doi":"10.1063/5.0223763","DOIUrl":"https://doi.org/10.1063/5.0223763","url":null,"abstract":"We studied the transport properties of graphene–insulator–metal tunneling diodes. Two sets of tunneling diodes with Ti–Cu and Cr–Au top contacts are fabricated. Transport measurements showed state-of-the-art non-linearity and a critical influence of the top metals on the dielectric strength of the tunneling barrier. X-ray photoelectron spectroscopy indicated two methods for enhancing the dielectric strength of the tunneling barrier. These are the optimized seed layers for the growth of high-quality conformal insulators and the selection of appropriate top metal layers with a small diffusion coefficient and electromigration into the Al2O3 barrier. The Cr–Au top contact provides superior characteristics to the Ti–Cu metallization. X-ray photoelectron spectroscopy showed significant diffusion of titanium during the Al2O3 growth and the formation of titanium inclusions after annealing. Chromium diffusion is slower than that of titanium, making chromium contact more suitable for the reliable operation of tunneling diodes. As a result, we demonstrate a 40% improvement in the dielectric strength of the tunneling barrier compared to state-of-the-art metal–insulator–metal diodes.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"61 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142185400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pengfei Yan, Guanqi Li, Zhihao Li, Yafei Zhao, Liang He
Owing to their distinctive novel properties, topological metals hold significant promise for application in spintronics, quantum computing, and superconductivity. Using first-principle calculations, we have elucidated the unfolding band structure of 3d transition metal (3d-TM)-doped CrTe2. Notably, our investigation has revealed band crossings in Cu-doped CrTe2, forming a nodal ring near the Fermi level. Through analyzing Wannier charge centers, we have established the topological nontriviality of CrTe2 upon Cu doping. This study demonstrates a fresh platform for exploring their inherent topological properties and introduces a novel perspective on tectonic topological metals.
拓扑金属具有与众不同的新颖特性，因此在自旋电子学、量子计算和超导领域有着广阔的应用前景。通过第一原理计算，我们阐明了 3d 过渡金属（3d-TM）掺杂 CrTe2 的展开带结构。值得注意的是，我们的研究揭示了铜掺杂 CrTe2 中的能带交叉，在费米级附近形成了一个节点环。通过分析万尼尔电荷中心，我们确定了掺铜后 CrTe2 的拓扑非惰性。这项研究为探索其固有拓扑特性提供了一个全新的平台，并为构造拓扑金属引入了一个新的视角。
{"title":"Unfolding band structure and topological property of 3d transition metal doped monolayer CrTe2: A first-principle calculation","authors":"Pengfei Yan, Guanqi Li, Zhihao Li, Yafei Zhao, Liang He","doi":"10.1063/5.0225476","DOIUrl":"https://doi.org/10.1063/5.0225476","url":null,"abstract":"Owing to their distinctive novel properties, topological metals hold significant promise for application in spintronics, quantum computing, and superconductivity. Using first-principle calculations, we have elucidated the unfolding band structure of 3d transition metal (3d-TM)-doped CrTe2. Notably, our investigation has revealed band crossings in Cu-doped CrTe2, forming a nodal ring near the Fermi level. Through analyzing Wannier charge centers, we have established the topological nontriviality of CrTe2 upon Cu doping. This study demonstrates a fresh platform for exploring their inherent topological properties and introduces a novel perspective on tectonic topological metals.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142185410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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