Cold spray is an effective method for surface coating, which has been applied in various engineering areas. However, it is difficult to directly observe the dynamic deformation process in experiments. This paper applies the molecular dynamics simulation to model the deposition of a monocrystalline Cu particle onto a Cu substrate and, subsequently, carries out a systematic study on the deposition mechanism and microstructure evolution. The results indicate that the deposition process consists of an impact stage and a relaxation stage. It is mainly the high speed collision and the friction following the collision that lead to particle deposition, which, under different circumstances, can be defined as surface deposition or penetration deposition. Two methods, namely, drastic shear deformation and cooling in the relaxation stage, can help form nanocrystallines. Jetting and melting are not the necessary factors for the deposition of nano-sized particles. The formation of dislocation lines is influenced by impact velocities. At lower impact velocities, the dislocation lines are mainly distributed near the contact surface. However, when the impact velocity is higher, dislocation lines are almost uniformly distributed in the particle.
{"title":"Atomistic simulation on the deposition behavior of cold spray","authors":"Jianrui Feng, Erfeng An, Wensen Zhao","doi":"10.1063/5.0218416","DOIUrl":"https://doi.org/10.1063/5.0218416","url":null,"abstract":"Cold spray is an effective method for surface coating, which has been applied in various engineering areas. However, it is difficult to directly observe the dynamic deformation process in experiments. This paper applies the molecular dynamics simulation to model the deposition of a monocrystalline Cu particle onto a Cu substrate and, subsequently, carries out a systematic study on the deposition mechanism and microstructure evolution. The results indicate that the deposition process consists of an impact stage and a relaxation stage. It is mainly the high speed collision and the friction following the collision that lead to particle deposition, which, under different circumstances, can be defined as surface deposition or penetration deposition. Two methods, namely, drastic shear deformation and cooling in the relaxation stage, can help form nanocrystallines. Jetting and melting are not the necessary factors for the deposition of nano-sized particles. The formation of dislocation lines is influenced by impact velocities. At lower impact velocities, the dislocation lines are mainly distributed near the contact surface. However, when the impact velocity is higher, dislocation lines are almost uniformly distributed in the particle.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"15 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Rui Jiang, Lei Gao, Lei Yang, Wenzhe He, Jun Wang, Qian Wu, Yong Sun, Quanying Wu, Yongqiang Chen
We present a novel approach for actively controlling electromagnetically induced transparency (EIT) analogs in a single-mode microstrip cavity. This cavity is side-coupled with a pair of varactor-loaded split-ring resonators (SRRs). The EIT-like effect is achieved through resonance hybridization between the paired SRRs with frequency detuning. The microstrip cavity is utilized to enhance the EIT-like transmission properties, including Q-factor and group delay. Varactor diodes, soldered at the gap of the SRRs, are biased electrically through a DC voltage source. This dynamic modulation setup allows for the tuning of the enhanced EIT analog. Experimental results demonstrate that the enhanced EIT-like transmission spectrum can be tuned reversibly by 378 MHz with respect to the transmission dip frequency of 2.464 GHz under the bias voltage ranging from 0 to 5 V. Simultaneously, the controlled transmission spectrum enables a remarkable change in group delay of 10.9 ns. Moreover, the modulation amplitude of the composite SRRs-cavity structure reaches a peak value of up to 34.5 dB, significantly higher than the 6.4 dB of the individual SRRs pair. These results hold promise for inspiring innovation in actively controlled photonic devices for practical applications.
我们提出了一种在单模微带腔中主动控制电磁诱导透明（EIT）类似物的新方法。该空腔侧面耦合了一对变容二极管加载的分环谐振器（SRR）。类似 EIT 的效果是通过频率失谐的成对 SRR 之间的共振杂化实现的。微带腔用于增强类 EIT 传输特性，包括 Q 因子和群延迟。焊接在 SRR 间隙的变容二极管通过直流电压源进行电偏压。这种动态调制设置允许对增强型 EIT 模拟进行调整。实验结果表明，在 0 至 5 V 的偏置电压下，增强型 EIT 类传输频谱可相对于 2.464 GHz 的传输骤降频率可逆地调整 378 MHz。与此同时，受控传输频谱还能使群延迟发生显著变化，达到 10.9 ns。此外，复合 SRRs-Cavity 结构的调制幅度峰值高达 34.5 dB，明显高于单个 SRRs 对的 6.4 dB。这些结果有望激发实际应用中主动控制光子器件的创新。
{"title":"Electromagnetic modulating action in a microstrip cavity with embedded two detuned resonators","authors":"Rui Jiang, Lei Gao, Lei Yang, Wenzhe He, Jun Wang, Qian Wu, Yong Sun, Quanying Wu, Yongqiang Chen","doi":"10.1063/5.0227168","DOIUrl":"https://doi.org/10.1063/5.0227168","url":null,"abstract":"We present a novel approach for actively controlling electromagnetically induced transparency (EIT) analogs in a single-mode microstrip cavity. This cavity is side-coupled with a pair of varactor-loaded split-ring resonators (SRRs). The EIT-like effect is achieved through resonance hybridization between the paired SRRs with frequency detuning. The microstrip cavity is utilized to enhance the EIT-like transmission properties, including Q-factor and group delay. Varactor diodes, soldered at the gap of the SRRs, are biased electrically through a DC voltage source. This dynamic modulation setup allows for the tuning of the enhanced EIT analog. Experimental results demonstrate that the enhanced EIT-like transmission spectrum can be tuned reversibly by 378 MHz with respect to the transmission dip frequency of 2.464 GHz under the bias voltage ranging from 0 to 5 V. Simultaneously, the controlled transmission spectrum enables a remarkable change in group delay of 10.9 ns. Moreover, the modulation amplitude of the composite SRRs-cavity structure reaches a peak value of up to 34.5 dB, significantly higher than the 6.4 dB of the individual SRRs pair. These results hold promise for inspiring innovation in actively controlled photonic devices for practical applications.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"16 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
K. Kan-Dapaah, J. A. Aidoo, B. Agyei-Tuffour, B. Mensah, A. Yaya, S. A. Abudu, S. W. K. Hatekah
Gold nanoparticles synthesized via honey-mediated chemical reduction have desirable features that make them ideal candidates for nanoparticle-assisted photothermal therapy (N-PTT). However, their photothermal properties have not been previously explored. In this study, after synthesis and characterization (structural and optical) of the HM-AuNPs, we investigated their photothermal conversion efficiency (η) and absorption cross section (σabs) in aqueous solution, cytotoxic effects in in vitro MDA-MB-468 breast cancer cell culture, and temperature profiles in agarose gel under 810 nm NIR irradiation. The results showed that ≈15 nm and primarily spherical HM-AuNPs had η values of up to 40% and an average σabs of 2.15±0.08×10−18 m2. Furthermore, cell viability was reduced to about 52% and the temperature profile in agarose gel had the typical radially increasing topology. Collectively, the findings show that HM-AuNPs can be used in N-PTT.
{"title":"Near-infrared irradiation study of honey-mediated Au nanoparticles for photothermal therapy","authors":"K. Kan-Dapaah, J. A. Aidoo, B. Agyei-Tuffour, B. Mensah, A. Yaya, S. A. Abudu, S. W. K. Hatekah","doi":"10.1063/5.0219146","DOIUrl":"https://doi.org/10.1063/5.0219146","url":null,"abstract":"Gold nanoparticles synthesized via honey-mediated chemical reduction have desirable features that make them ideal candidates for nanoparticle-assisted photothermal therapy (N-PTT). However, their photothermal properties have not been previously explored. In this study, after synthesis and characterization (structural and optical) of the HM-AuNPs, we investigated their photothermal conversion efficiency (η) and absorption cross section (σabs) in aqueous solution, cytotoxic effects in in vitro MDA-MB-468 breast cancer cell culture, and temperature profiles in agarose gel under 810 nm NIR irradiation. The results showed that ≈15 nm and primarily spherical HM-AuNPs had η values of up to 40% and an average σabs of 2.15±0.08×10−18 m2. Furthermore, cell viability was reduced to about 52% and the temperature profile in agarose gel had the typical radially increasing topology. Collectively, the findings show that HM-AuNPs can be used in N-PTT.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"115 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
The ionic conductivity at the grain boundaries (GBs) in oxide ceramics is typically several orders of magnitude lower than that within the grain interior. This detrimental GB effect is the main bottleneck for designing high-performance ceramic electrolytes intended for use in solid-state lithium-ion batteries, fuel cells, and electrolyzer cells. The macroscopic ionic conductivity in oxide ceramics is essentially governed by the underlying polycrystalline microstructures where GBs and grain morphology go hand in hand. This provides the possibility to enhance the ion conductivity by microstructure engineering. To this end, a thorough understanding of microstructure–property correlation is highly desirable. In this work, we investigate numerous polycrystalline microstructure samples with varying grain and grain boundary features. Their macroscopic ionic conductivities are numerically evaluated by the finite element homogenization method, whereby the GB resistance is explicitly regarded. The influence of different microstructural features on the effective ionic conductivity is systematically studied. The microstructure–property relationships are revealed. Additionally, a graph neural network-based machine learning model is constructed and trained. It can accurately predict the effective ionic conductivity for a given polycrystalline microstructure. This work provides crucial quantitative guidelines for optimizing the ionic conducting performance of oxide ceramics by tailoring microstructures.
{"title":"Unraveling impacts of polycrystalline microstructures on ionic conductivity of ceramic electrolytes by computational homogenization and machine learning","authors":"Xiang-Long Peng, Bai-Xiang Xu","doi":"10.1063/5.0223138","DOIUrl":"https://doi.org/10.1063/5.0223138","url":null,"abstract":"The ionic conductivity at the grain boundaries (GBs) in oxide ceramics is typically several orders of magnitude lower than that within the grain interior. This detrimental GB effect is the main bottleneck for designing high-performance ceramic electrolytes intended for use in solid-state lithium-ion batteries, fuel cells, and electrolyzer cells. The macroscopic ionic conductivity in oxide ceramics is essentially governed by the underlying polycrystalline microstructures where GBs and grain morphology go hand in hand. This provides the possibility to enhance the ion conductivity by microstructure engineering. To this end, a thorough understanding of microstructure–property correlation is highly desirable. In this work, we investigate numerous polycrystalline microstructure samples with varying grain and grain boundary features. Their macroscopic ionic conductivities are numerically evaluated by the finite element homogenization method, whereby the GB resistance is explicitly regarded. The influence of different microstructural features on the effective ionic conductivity is systematically studied. The microstructure–property relationships are revealed. Additionally, a graph neural network-based machine learning model is constructed and trained. It can accurately predict the effective ionic conductivity for a given polycrystalline microstructure. This work provides crucial quantitative guidelines for optimizing the ionic conducting performance of oxide ceramics by tailoring microstructures.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"61 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2024-09-07Epub Date: 2024-09-04DOI: 10.1063/5.0218262
Stephanie N Kramer, Jeanpun Antarasen, Cole R Reinholt, Lydia Kisley
We present a comprehensive guide to light-sheet microscopy (LSM) to assist scientists in navigating the practical implementation of this microscopy technique. Emphasizing the applicability of LSM to image both static microscale and nanoscale features, as well as diffusion dynamics, we present the fundamental concepts of microscopy, progressing through beam profile considerations, to image reconstruction. We outline key practical decisions in constructing a home-built system and provide insight into the alignment and calibration processes. We briefly discuss the conditions necessary for constructing a continuous 3D image and introduce our home-built code for data analysis. By providing this guide, we aim to alleviate the challenges associated with designing and constructing LSM systems and offer scientists new to LSM a valuable resource in navigating this complex field.
{"title":"A practical guide to light-sheet microscopy for nanoscale imaging: Looking beyond the cell.","authors":"Stephanie N Kramer, Jeanpun Antarasen, Cole R Reinholt, Lydia Kisley","doi":"10.1063/5.0218262","DOIUrl":"10.1063/5.0218262","url":null,"abstract":"<p><p>We present a comprehensive guide to light-sheet microscopy (LSM) to assist scientists in navigating the practical implementation of this microscopy technique. Emphasizing the applicability of LSM to image both static microscale and nanoscale features, as well as diffusion dynamics, we present the fundamental concepts of microscopy, progressing through beam profile considerations, to image reconstruction. We outline key practical decisions in constructing a home-built system and provide insight into the alignment and calibration processes. We briefly discuss the conditions necessary for constructing a continuous 3D image and introduce our home-built code for data analysis. By providing this guide, we aim to alleviate the challenges associated with designing and constructing LSM systems and offer scientists new to LSM a valuable resource in navigating this complex field.</p>","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"136 9","pages":"091101"},"PeriodicalIF":2.7,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11380115/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142154063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Deep levels in the whole bandgap of 4H-SiC generated by reactive ion etching (RIE) are investigated with both n- and p-type SiC Schottky barrier diodes by deep-level transient spectroscopy (DLTS). Depth profiles of the observed deep levels were analyzed using the DLTS peak intensities at various bias voltages and numerical calculations. The major electron traps detected after RIE and subsequent annealing at 1300 °C include the Z1/2 (EC−0.66 eV), ON1 (EC−0.88 eV), ON2 (EC−0.95 eV), and EH6/7 (EC−1.50 eV) centers, and the major hole traps include the UK1 (EV+0.51 eV), UK2 (EV+0.72 eV), HK0 (EV+0.77 eV), HK2 (EV+0.79 eV), and HK3 (EV+1.31 eV) centers, where EC and EV denote the conduction and valence band edges, respectively. Most of the traps were localized near the surface (<0.5 μm) with a maximum density of about 1×1015 cm−3, but several traps such as the ON1 and HK0 centers penetrate deep into the bulk region (>2 μm). By annealing at 1400 °C, most of the hole traps were eliminated, but several electron traps remained. From these results, the origins of these defects are discussed.
通过深电平瞬态光谱 (DLTS)，研究了反应离子蚀刻 (RIE) 在 n 型和 p 型 SiC 肖特基势垒二极管中产生的 4H-SiC 全带隙深电平。利用不同偏置电压下的 DLTS 峰强度和数值计算分析了观察到的深电平深度剖面。经过 RIE 和 1300 °C 退火后检测到的主要电子陷阱包括 Z1/2（EC-0.66 eV）、ON1（EC-0.88 eV）、ON2（EC-0.95 eV）和 EH6/7（EC-1.50 eV）中心，而主要的空穴陷阱包括 UK1（EV+0.51 eV）、UK2（EV+0.72 eV）、HK0（EV+0.77 eV）、HK2（EV+0.79 eV）和 HK3（EV+1.31 eV）中心，其中 EC 和 EV 分别表示导带和价带边缘。大多数陷阱都集中在表面附近（<0.5 μm），最大密度约为 1×1015 cm-3，但也有几个陷阱，如 ON1 和 HK0 中心，深入到体层区域（>2 μm）。在 1400 °C 退火后，大部分空穴陷阱被消除，但仍有几个电子陷阱存在。根据这些结果，我们讨论了这些缺陷的起源。
{"title":"Depth profiles of electron and hole traps generated by reactive ion etching near the surface of 4H-SiC","authors":"Shota Kozakai, Haruki Fujii, Mitsuaki Kaneko, Tsunenobu Kimoto","doi":"10.1063/5.0221700","DOIUrl":"https://doi.org/10.1063/5.0221700","url":null,"abstract":"Deep levels in the whole bandgap of 4H-SiC generated by reactive ion etching (RIE) are investigated with both n- and p-type SiC Schottky barrier diodes by deep-level transient spectroscopy (DLTS). Depth profiles of the observed deep levels were analyzed using the DLTS peak intensities at various bias voltages and numerical calculations. The major electron traps detected after RIE and subsequent annealing at 1300 °C include the Z1/2 (EC−0.66 eV), ON1 (EC−0.88 eV), ON2 (EC−0.95 eV), and EH6/7 (EC−1.50 eV) centers, and the major hole traps include the UK1 (EV+0.51 eV), UK2 (EV+0.72 eV), HK0 (EV+0.77 eV), HK2 (EV+0.79 eV), and HK3 (EV+1.31 eV) centers, where EC and EV denote the conduction and valence band edges, respectively. Most of the traps were localized near the surface (&lt;0.5 μm) with a maximum density of about 1×1015 cm−3, but several traps such as the ON1 and HK0 centers penetrate deep into the bulk region (&gt;2 μm). By annealing at 1400 °C, most of the hole traps were eliminated, but several electron traps remained. From these results, the origins of these defects are discussed.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"43 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
In this work, we explore the physics and evaluate the merits of strain engineering in two-dimensional van der Waals semiconductor-based FETs (field-effect-transistors) using DFT (density functional theory) to determine the modulation of the channel material properties under strain, and subsequently, their effect on carrier transport properties, i.e., scattering rates, mobility, and then finally simulate and analyze dissipative current transport with a non-equilibrium Green's function–Poisson's equation self-consistent solver. The scattering model includes the effects of charged impurities, intrinsic phonons, and remote phonons as well as the screening effect due to charged carriers. Impact of strain engineering on contact resistance is also incorporated into the transport simulations to determine the potential performance enhancements using strain in practical devices. Based on the comprehensive simulation results, we identify the materials and strain configuration that provide the best improvement in performance. We demonstrate an ON-current gain of 43.3% in a biaxially compressively strained monolayer MoSe2 device achieved through unique valley-crossing. Furthermore, implications of strain engineering for emerging energy-efficient devices based on band-to-band tunneling and spintronics are evaluated to explore uncharted frontiers in beyond-CMOS electron devices.
{"title":"Strain engineering in 2D FETs: Physics, status, and prospects","authors":"Ankit Kumar, Lin Xu, Arnab Pal, Kunjesh Agashiwala, Kamyar Parto, Wei Cao, Kaustav Banerjee","doi":"10.1063/5.0211555","DOIUrl":"https://doi.org/10.1063/5.0211555","url":null,"abstract":"In this work, we explore the physics and evaluate the merits of strain engineering in two-dimensional van der Waals semiconductor-based FETs (field-effect-transistors) using DFT (density functional theory) to determine the modulation of the channel material properties under strain, and subsequently, their effect on carrier transport properties, i.e., scattering rates, mobility, and then finally simulate and analyze dissipative current transport with a non-equilibrium Green's function–Poisson's equation self-consistent solver. The scattering model includes the effects of charged impurities, intrinsic phonons, and remote phonons as well as the screening effect due to charged carriers. Impact of strain engineering on contact resistance is also incorporated into the transport simulations to determine the potential performance enhancements using strain in practical devices. Based on the comprehensive simulation results, we identify the materials and strain configuration that provide the best improvement in performance. We demonstrate an ON-current gain of 43.3% in a biaxially compressively strained monolayer MoSe2 device achieved through unique valley-crossing. Furthermore, implications of strain engineering for emerging energy-efficient devices based on band-to-band tunneling and spintronics are evaluated to explore uncharted frontiers in beyond-CMOS electron devices.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"9 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Mochammad Yan Pandu Akbar, Syafitra Salam, Cristoph P. Grams, Markus Diantoro, Bambang Prijamboedi, Joachim Hemberger, Agustinus Agung Nugroho
The dynamics of spin and charge-ordered phases in La1.67Sr0.33NiO4 single crystal have been investigated using high-frequency dielectric spectroscopy. The measurements were carried out in frequencies between 0.156 and 316 MHz and temperatures from 50 to 320 K. The intrinsic part of the response by excluding the Maxwell–Wagner relaxation region is obtained below TSDW ∼ 120 K. The intrinsic frequency-dependent real dielectric constant ɛ′ and conductivity σ′ can be well described in terms of the constant phase element revealing a complex charge-hopping process. Our results are in agreement with the spin-density-wave puddles’ picture observed by the scanning micro-x-ray diffraction technique. These demonstrate that high-frequency dielectric spectroscopy can be utilized for investigating the various order phases in other transition metal oxides by considering their intrinsic responses.
我们使用高频介电光谱法研究了 La1.67Sr0.33NiO4 单晶中自旋和电荷有序相的动力学。测量在 0.156 至 316 MHz 的频率和 50 至 320 K 的温度范围内进行。通过排除麦克斯韦尔-瓦格纳弛豫区，得到了低于 TSDW ∼ 120 K 的固有响应部分。我们的研究结果与扫描微 X 射线衍射技术观察到的自旋密度波坑图像一致。这些结果表明，通过考虑其他过渡金属氧化物的固有响应，可以利用高频介电光谱来研究它们的各种有序相。
{"title":"Dielectric responses of spin-density wave in La1.67Sr0.33NiO4 single crystal","authors":"Mochammad Yan Pandu Akbar, Syafitra Salam, Cristoph P. Grams, Markus Diantoro, Bambang Prijamboedi, Joachim Hemberger, Agustinus Agung Nugroho","doi":"10.1063/5.0219900","DOIUrl":"https://doi.org/10.1063/5.0219900","url":null,"abstract":"The dynamics of spin and charge-ordered phases in La1.67Sr0.33NiO4 single crystal have been investigated using high-frequency dielectric spectroscopy. The measurements were carried out in frequencies between 0.156 and 316 MHz and temperatures from 50 to 320 K. The intrinsic part of the response by excluding the Maxwell–Wagner relaxation region is obtained below TSDW ∼ 120 K. The intrinsic frequency-dependent real dielectric constant ɛ′ and conductivity σ′ can be well described in terms of the constant phase element revealing a complex charge-hopping process. Our results are in agreement with the spin-density-wave puddles’ picture observed by the scanning micro-x-ray diffraction technique. These demonstrate that high-frequency dielectric spectroscopy can be utilized for investigating the various order phases in other transition metal oxides by considering their intrinsic responses.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"172 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Kirstin Alberi, Chase Brooks, Ian Leahy, Stephan Lany
Three-dimensional topological semimetals are a class of electronic materials in which their bulk and surface states contain linear band touching nodes near the Fermi level. Like semiconductors, their properties will be affected by point and extended defects in their crystal structures, although the extent to which defects and disorders influence topological semimetals may differ in key ways due to their unique electronic structures. In this Tutorial, we provide an overview of the defects in topological semimetals, covering both computational and experimental methods for exploring defect-property relationships. We also include a discussion on open questions that still need to be explored further.
{"title":"Tutorial: Defects in topological semimetals","authors":"Kirstin Alberi, Chase Brooks, Ian Leahy, Stephan Lany","doi":"10.1063/5.0217533","DOIUrl":"https://doi.org/10.1063/5.0217533","url":null,"abstract":"Three-dimensional topological semimetals are a class of electronic materials in which their bulk and surface states contain linear band touching nodes near the Fermi level. Like semiconductors, their properties will be affected by point and extended defects in their crystal structures, although the extent to which defects and disorders influence topological semimetals may differ in key ways due to their unique electronic structures. In this Tutorial, we provide an overview of the defects in topological semimetals, covering both computational and experimental methods for exploring defect-property relationships. We also include a discussion on open questions that still need to be explored further.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"18 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
James G. Boyd, Dimitrios Loufakis, Jodie L. Lutkenhaus
The motion of ions in supercapacitor electrodes produces internal stresses that cause viscoelastic strains. In addition, stresses may be due to external forces applied to structural supercapacitors, which are multifunctional materials that simultaneously store energy and carry structural loads. There are currently no thermodynamics-based models for the coupled electro-chemo-viscoelastic response of electrodes. Here, the same thermodynamics model is used for both the viscoelastic response and the electrochemical response. This mathematical equivalence is a reference from which to study coupling between the viscoelastic and electrochemical responses. The model has two inputs (stress or strain and electric potential or specific charge) and two outputs (strain or stress and specific charge or electric potential). The coupling is studied by adding three constants in the free energy. The convexity of the free energy and the stability of the free response limit the magnitude of the coupling. The unit response matrix is derived, and results are given for the time and frequency domains. The effect of an applied potential on stress is shown to be much more significant than the converse effect. The model compares well to an experiment consisting of a cyclic electric current applied during stress relaxation.
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