Pub Date : 2024-07-24DOI: 10.1088/1361-6463/ad5b70
Vitaly Yu Topolov
The results of a comparative study on piezo-active 2–1–2 composites with two ferroelectric components are discussed. The composite structure combines elements of 2–2 (laminar) and 1–3 (fibrous) connectivity patterns. The first component in each composite is domain-engineered [0 1 1]-poled single crystal with macroscopic mm2 symmetry and high piezoelectric activity. The second component is a poled ferroelectric ceramic that is represented by parallel rods in the shape of an elliptic cylinder with a large ratio of semi-axes at its base. The first orientation effect is appreciable due to rotations of the main crystallographic axes X and Y around Z || OX3 by an angle α in each crystal layer. Rotation of the ceramic rod bases by an angle γ in a polymer medium leads to the second orientation effect in the 2–1–2 composite. The two orientation effects contribute to a large anisotropy of electromechanical coupling factors , energy-harvesting figures of merit (FOM) and modified FOM for a stress-driven harvester. The large level of , , and (these parameters are of the order of 10−11–10−10 Pa−1) indicates that the studied composites are suitable for piezoelectric sensors, transducers and energy-harvesting systems. New m—α diagrams put forward in the present study show regions wherein the large anisotropy of the effective parameters ( / , )2 and , f = 1 and 2) is achieved when changing the volume fraction m of the single crystal and the rotation angle α. As a result, the leading role of the first orientation effect is emphasised.
本文讨论了对含有两种铁电成分的压电活性 2-1-2 复合材料进行比较研究的结果。复合材料结构结合了 2-2（层状）和 1-3（纤维状）连接模式的元素。每种复合材料的第一种成分是畴工程[0 1 1]极化单晶，具有宏观 mm2 对称性和高压电活性。第二种成分是极化铁电陶瓷，它由平行棒组成，呈椭圆柱状，底部的半轴比很大。由于每个晶体层中的主要晶体学轴 X 和 Y 围绕 Z || OX3 旋转了 α 角，因此第一种取向效应非常明显。陶瓷棒基在聚合物介质中旋转 γ 角导致了 2-1-2 复合材料中的第二种取向效应。这两种取向效应导致机电耦合系数、能量收集功勋值（FOM）和应力驱动收集器的修正 FOM 存在较大的各向异性。较大的、、和（这些参数的数量级为 10-11-10-10 Pa-1）表明，所研究的复合材料适用于压电传感器、换能器和能量收集系统。本研究提出的新 m-α 图显示，当改变单晶体的体积分数 m 和旋转角度 α 时，有效参数 ( / , )2 和 , f = 1 和 2) 的大各向异性区域。因此，第一取向效应的主导作用得到了强调。
{"title":"Two orientation effects and large anisotropy of parameters in piezo-active 2–1–2 composites based on [0 1 1]-poled crystals","authors":"Vitaly Yu Topolov","doi":"10.1088/1361-6463/ad5b70","DOIUrl":"https://doi.org/10.1088/1361-6463/ad5b70","url":null,"abstract":"The results of a comparative study on piezo-active 2–1–2 composites with two ferroelectric components are discussed. The composite structure combines elements of 2–2 (laminar) and 1–3 (fibrous) connectivity patterns. The first component in each composite is domain-engineered [0 1 1]-poled single crystal with macroscopic mm2 symmetry and high piezoelectric activity. The second component is a poled ferroelectric ceramic that is represented by parallel rods in the shape of an elliptic cylinder with a large ratio of semi-axes at its base. The first orientation effect is appreciable due to rotations of the main crystallographic axes X and Y around Z || OX3 by an angle α in each crystal layer. Rotation of the ceramic rod bases by an angle γ in a polymer medium leads to the second orientation effect in the 2–1–2 composite. The two orientation effects contribute to a large anisotropy of electromechanical coupling factors , energy-harvesting figures of merit (FOM) and modified FOM for a stress-driven harvester. The large level of , , and (these parameters are of the order of 10−11–10−10 Pa−1) indicates that the studied composites are suitable for piezoelectric sensors, transducers and energy-harvesting systems. New m—α diagrams put forward in the present study show regions wherein the large anisotropy of the effective parameters ( / , )2 and , f = 1 and 2) is achieved when changing the volume fraction m of the single crystal and the rotation angle α. As a result, the leading role of the first orientation effect is emphasised.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"21 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141783208","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 : 2024-07-22DOI: 10.1088/1361-6463/ad5b02
Roman B Morgunov, Sergey N Kashin, Ekaterina I Kunitsyna, Artem D Talantsev and Aleksander I Chernov
Multiple noncollinear spin structures and transitions between them initiated by field and temperature have attracted attention due to the extraordinary coexistence of complicated spin phases in Ho. We explore the magnetic relaxation dynamics within thin films undergoing transitions between ferromagnetic (FM) and helix states. When measuring susceptibility in a relatively high frequency range (∼100–1500 Hz) and magnetic viscosity at lower frequency (∼0.01 Hz), we focus on 400 nm thick Ho film. Notably, sharp variations in the real and imaginary components of magnetic susceptibility are discerned during the FM – Helix transition, occurring at temperatures between 15 and 30 K. Hysteresis effects in the magnetic susceptibility components are identified during cyclic variations in the external field, indicating a relatively rapid process with a timescale of approximately 10 ms accompanying the FM – Helix transition. The slow relaxation process is also found to exhibit sensitivity to this transition. Furthermore, the field dependence of magnetic viscosity displays a marked decline at the FM – Helix transition. The research methodologies proposed for the investigation of relaxation processes in materials with multiphase spin structures are deemed universally applicable and offer insights into transitions between spin states in materials manifesting non collinear spin structures.
多种非共轭自旋结构以及由磁场和温度引发的它们之间的转变引起了人们的关注，因为在 Ho 中复杂的自旋相非同寻常地共存。我们探索了在铁磁（FM）态和螺旋态之间发生转变的薄膜内部的磁弛豫动力学。在测量相对较高频率范围（∼100-1500 Hz）的磁感应强度和较低频率（∼0.01 Hz）的磁粘性时，我们以 400 nm 厚的 Ho 薄膜为研究对象。值得注意的是，在调频-螺旋转换期间，磁感应强度的实分量和虚分量发生了急剧变化，发生在 15 至 30 K 的温度范围内。在外部磁场周期性变化期间，磁感应强度分量的磁滞效应被识别出来，这表明调频-螺旋转换是一个相对快速的过程，时间尺度约为 10 ms。此外，还发现缓慢的弛豫过程对这一转变非常敏感。此外，磁性粘度的磁场依赖性在调频-螺旋转换时明显下降。为研究具有多相自旋结构的材料中的弛豫过程而提出的研究方法被认为是普遍适用的，并为研究具有非对偶自旋结构的材料中自旋态之间的转变提供了见解。
{"title":"Magnetic relaxation between ferromagnetic and helix spin configurations in holmium films","authors":"Roman B Morgunov, Sergey N Kashin, Ekaterina I Kunitsyna, Artem D Talantsev and Aleksander I Chernov","doi":"10.1088/1361-6463/ad5b02","DOIUrl":"https://doi.org/10.1088/1361-6463/ad5b02","url":null,"abstract":"Multiple noncollinear spin structures and transitions between them initiated by field and temperature have attracted attention due to the extraordinary coexistence of complicated spin phases in Ho. We explore the magnetic relaxation dynamics within thin films undergoing transitions between ferromagnetic (FM) and helix states. When measuring susceptibility in a relatively high frequency range (∼100–1500 Hz) and magnetic viscosity at lower frequency (∼0.01 Hz), we focus on 400 nm thick Ho film. Notably, sharp variations in the real and imaginary components of magnetic susceptibility are discerned during the FM – Helix transition, occurring at temperatures between 15 and 30 K. Hysteresis effects in the magnetic susceptibility components are identified during cyclic variations in the external field, indicating a relatively rapid process with a timescale of approximately 10 ms accompanying the FM – Helix transition. The slow relaxation process is also found to exhibit sensitivity to this transition. Furthermore, the field dependence of magnetic viscosity displays a marked decline at the FM – Helix transition. The research methodologies proposed for the investigation of relaxation processes in materials with multiphase spin structures are deemed universally applicable and offer insights into transitions between spin states in materials manifesting non collinear spin structures.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"78 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141753989","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 : 2024-07-22DOI: 10.1088/1361-6463/ad5f9b
Fen Zhao, Baoze Huang, Qingxiao Liu and Junbo Yang
A design method is proposed for a broadband super-resolution wavelength-controlled zoom metalens with simultaneous modulation of phase, dispersion, and amplitude, and on the basis of enhancing the axial zoom capability of the metalens, the point spread function of the metalens is continuously compressed using the hierarchical direct binary search algorithm, so that the full width at half maximum of the metalens is continuously close to or even less than the diffraction limit of 0.5λ/NA (NA is the numerical aperture). As a theoretical verification, a super-resolution wavelength-controlled zoom metalens was designed operating in the wavelength range of 68–80 μm. The simulation results show that its axial zoom capability is about 1.65 times that of the conventional diffractive metalens, and the lateral resolution in the wavelength range of 68–80 μm is less than the diffraction limit.
{"title":"Broadband super-resolution wavelength-controlled zoom metalens","authors":"Fen Zhao, Baoze Huang, Qingxiao Liu and Junbo Yang","doi":"10.1088/1361-6463/ad5f9b","DOIUrl":"https://doi.org/10.1088/1361-6463/ad5f9b","url":null,"abstract":"A design method is proposed for a broadband super-resolution wavelength-controlled zoom metalens with simultaneous modulation of phase, dispersion, and amplitude, and on the basis of enhancing the axial zoom capability of the metalens, the point spread function of the metalens is continuously compressed using the hierarchical direct binary search algorithm, so that the full width at half maximum of the metalens is continuously close to or even less than the diffraction limit of 0.5λ/NA (NA is the numerical aperture). As a theoretical verification, a super-resolution wavelength-controlled zoom metalens was designed operating in the wavelength range of 68–80 μm. The simulation results show that its axial zoom capability is about 1.65 times that of the conventional diffractive metalens, and the lateral resolution in the wavelength range of 68–80 μm is less than the diffraction limit.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"49 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141753990","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}
Flexoelectricity, denoted as an electromechanical coupling effect from strain gradient introduced polarization, is prevalent in dielectric materials. However, its application in low-viscosity liquids has been limited by the scale of the flexoelectric coefficient. This study explores the flexoelectric coefficient of various hydrated ion solutions through a series of experiments. Additionally, the interplay between ion adsorption and the flexoelectric effect is investigated by using interfacial voltage detection. By introducing hydrated structures into liquids, a significant enlargement of the flexoelectric coefficient up to 2.3 × 10−9 C m−1 is obtained in Fe2(SO4)3 solution by four times than DI water. These findings highlight the remarkable electromechanical properties of liquid materials with hydrated ions and suggest promising avenues for the application of liquid dielectrics in hydrovoltaic technology, ionotronic devices, and energy harvesters.
挠电效应是由应变梯度引入极化的机电耦合效应，在介电材料中十分普遍。然而，其在低粘度液体中的应用一直受到挠电系数尺度的限制。本研究通过一系列实验探索了各种水合离子溶液的挠电系数。此外，还利用界面电压检测法研究了离子吸附与挠电效应之间的相互作用。通过在液体中引入水合结构，Fe2(SO4)3 溶液中的挠电系数显著增大至 2.3 × 10-9 C m-1，是去离子水的四倍。这些发现凸显了含有水合离子的液体材料的卓越机电特性，并为液体电介质在水伏特技术、离子电子器件和能量收集器中的应用提供了前景广阔的途径。
{"title":"Enhanced flexoelectricity of liquid with hydrated ions","authors":"Yifan Li, Yanyu Li, Xingjian Feng, Chongpu Zhai, Shuwen Zhang and Minglong Xu","doi":"10.1088/1361-6463/ad632f","DOIUrl":"https://doi.org/10.1088/1361-6463/ad632f","url":null,"abstract":"Flexoelectricity, denoted as an electromechanical coupling effect from strain gradient introduced polarization, is prevalent in dielectric materials. However, its application in low-viscosity liquids has been limited by the scale of the flexoelectric coefficient. This study explores the flexoelectric coefficient of various hydrated ion solutions through a series of experiments. Additionally, the interplay between ion adsorption and the flexoelectric effect is investigated by using interfacial voltage detection. By introducing hydrated structures into liquids, a significant enlargement of the flexoelectric coefficient up to 2.3 × 10−9 C m−1 is obtained in Fe2(SO4)3 solution by four times than DI water. These findings highlight the remarkable electromechanical properties of liquid materials with hydrated ions and suggest promising avenues for the application of liquid dielectrics in hydrovoltaic technology, ionotronic devices, and energy harvesters.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"1 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141753991","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 : 2024-07-21DOI: 10.1088/1361-6463/ad61f4
Nilton F Azevedo Neto, Felipe S Miranda, Pedro W P Moreira Junior, Marcelo P Gomes, Clodomiro Alves Junior, Cristiane Y Koga-Ito and Rodrigo S Pessoa
This research explores the synergistic application of Dielectric Barrier Discharge (DBD) and Gliding Arc Plasma Jet (GAPJ) in a Hybrid Plasma Discharge (HPD) setup for enhanced water activation. The HPD system demonstrated balanced and sustained generation of reactive oxygen and nitrogen species (RONS), maintaining efficiency at higher specific input energy (SIE) values. Comparative analyses with DBD and GAPJ systems highlighted the superior performance of the HPD system in generating RONS and modifying water’s molecular structure. Key observations included a decrease in water’s pH and an increase in oxidation-reduction potential, total dissolved solids, and conductivity, stabilizing beyond 5 l min−1 airflow and 10 min of treatment. UV−Vis spectroscopy identified nitrites, nitrates, hydrogen peroxide, and nitrous acid, while Raman spectroscopy captured shifts in vibrational modes, particularly in librational and O–H stretching bands. These changes correlated with alterations in reactive species concentrations and pH levels. Overall, the HPD system emerged as a versatile and efficient approach for generating plasma-activated water, suitable for applications in microbial deactivation, surface sterilization, and electrocatalytic process optimization, offering stable and continuous production of reactive species across a range of SIE values.
{"title":"Physical and chemical characteristics of plasma-activated water generated by hybrid dielectric barrier discharge and gliding arc discharge","authors":"Nilton F Azevedo Neto, Felipe S Miranda, Pedro W P Moreira Junior, Marcelo P Gomes, Clodomiro Alves Junior, Cristiane Y Koga-Ito and Rodrigo S Pessoa","doi":"10.1088/1361-6463/ad61f4","DOIUrl":"https://doi.org/10.1088/1361-6463/ad61f4","url":null,"abstract":"This research explores the synergistic application of Dielectric Barrier Discharge (DBD) and Gliding Arc Plasma Jet (GAPJ) in a Hybrid Plasma Discharge (HPD) setup for enhanced water activation. The HPD system demonstrated balanced and sustained generation of reactive oxygen and nitrogen species (RONS), maintaining efficiency at higher specific input energy (SIE) values. Comparative analyses with DBD and GAPJ systems highlighted the superior performance of the HPD system in generating RONS and modifying water’s molecular structure. Key observations included a decrease in water’s pH and an increase in oxidation-reduction potential, total dissolved solids, and conductivity, stabilizing beyond 5 l min−1 airflow and 10 min of treatment. UV−Vis spectroscopy identified nitrites, nitrates, hydrogen peroxide, and nitrous acid, while Raman spectroscopy captured shifts in vibrational modes, particularly in librational and O–H stretching bands. These changes correlated with alterations in reactive species concentrations and pH levels. Overall, the HPD system emerged as a versatile and efficient approach for generating plasma-activated water, suitable for applications in microbial deactivation, surface sterilization, and electrocatalytic process optimization, offering stable and continuous production of reactive species across a range of SIE values.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"13 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141743169","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 : 2024-07-21DOI: 10.1088/1361-6463/ad6267
Airi Nakayama, Siwei Liu, Ken-ichi Yano, Tomoki Nakajima and Takehiko Sato
Plasma medicine is a novel field of research that has the potential in life sciences, including cancer treatment. It has been believed that all of these potential applications depend on the chemical factor of the plasma. However, the electrical factors that are produced simultaneously with the chemical factors have not been researched thoroughly. To assess the effect of plasma on the response of cells, a system that enables simultaneous comparison of the effects of chemical and electrical factors of plasma with equal electricity was invented. This system separates the polarity of plasma and isolates the chemical species from the electric stimulation. Using this system, HT-1080 cells were exposed to plasma for 10 min, 1 h, and 24 h. The 10 min plasma treatment showed a clear difference in the polarity of plasma, where cells under exposure to positive plasma died while cells in other conditions survived. An hour of plasma treatment affected the cells under the negative plasma, where the cell viability was reduced to half. Meanwhile, the electric stimulation did not affect the cell viability but did alter the cell membrane. Collectively, this study demonstrates the differential effects of three factors (electric factor, positive plasma, negative plasma) under the same condition: both the electrical and chemical effects of plasma-generated stimuli with equal amounts of electricity were successfully observed.
{"title":"Cellular response to plasma-generated electrical and chemical stimulation of equal electricity","authors":"Airi Nakayama, Siwei Liu, Ken-ichi Yano, Tomoki Nakajima and Takehiko Sato","doi":"10.1088/1361-6463/ad6267","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6267","url":null,"abstract":"Plasma medicine is a novel field of research that has the potential in life sciences, including cancer treatment. It has been believed that all of these potential applications depend on the chemical factor of the plasma. However, the electrical factors that are produced simultaneously with the chemical factors have not been researched thoroughly. To assess the effect of plasma on the response of cells, a system that enables simultaneous comparison of the effects of chemical and electrical factors of plasma with equal electricity was invented. This system separates the polarity of plasma and isolates the chemical species from the electric stimulation. Using this system, HT-1080 cells were exposed to plasma for 10 min, 1 h, and 24 h. The 10 min plasma treatment showed a clear difference in the polarity of plasma, where cells under exposure to positive plasma died while cells in other conditions survived. An hour of plasma treatment affected the cells under the negative plasma, where the cell viability was reduced to half. Meanwhile, the electric stimulation did not affect the cell viability but did alter the cell membrane. Collectively, this study demonstrates the differential effects of three factors (electric factor, positive plasma, negative plasma) under the same condition: both the electrical and chemical effects of plasma-generated stimuli with equal amounts of electricity were successfully observed.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"90 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141743170","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 : 2024-07-17DOI: 10.1088/1361-6463/ad5b6f
Vaibhavi Gulavani, Musthafa Ottakam Thotiyl, Bibin John and Ashish Yengantiwar
The present work emphases on the post-mortem study of silica/carbon composite as functional anode in Li-ion batteries (LIBs). Herein, the silica/carbon composite is synthesized by facile in-situ hydrothermal technique. The x-ray diffraction (XRD) pattern indicates the amorphous nature of silica/carbon composite. The stacked sheet-like morphology of silica/carbon composite is seen in the high-resolution transmission electron microscopy (HR-TEM) & scanning electron microscopy (SEM) images. In addition, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, energy dispersive x-ray analysis (EDAX), and x-ray photoelectron spectra (XPS) characterizations of silica/carbon composite has been studied in detail. The rate capability of silica/carbon composite anode in LIB indicates 99% capacity retention after applying current density ranging from 50 mA g−1 to 1000 mA g−1, successively. The composite anode delivers a stable specific capacity ∼300 mAh g−1 at a current density of 100 mA g−1 for 500 cycles. Electrochemical impedance spectroscopy (EIS) study analyzed the faster Li-ion diffusion and increment in the diffusion coefficient by a factor of 1000 after 500 cycles. To the best of our knowledge, this is the first work on the post-mortem study of silica/carbon composite as anode in LIB. Post-cycling characterizations including XRD, FTIR, and SEM reveal the absence of any impurity phases and negligible volumetric expansion after prolonged cycling. It further confirms that the carbon present in the silica/carbon composite helps to accommodate the volumetric expansion of silica and prevents cracking of the anode over 500 cycles.
本研究的重点是对二氧化硅/碳复合材料作为锂离子电池（LIB）功能阳极的后期研究。本文采用简便的原位水热技术合成了二氧化硅/碳复合材料。X 射线衍射（XRD）图表明二氧化硅/碳复合材料具有无定形性质。从高分辨率透射电子显微镜（HR-TEM）和扫描电子显微镜（SEM）图像中可以看到二氧化硅/碳复合材料的叠层片状形态。此外，还详细研究了二氧化硅/碳复合材料的拉曼光谱、傅立叶变换红外光谱、能量色散 X 射线分析和 X 射线光电子能谱特性。二氧化硅/碳复合阳极在 LIB 中的速率能力表明，在电流密度从 50 mA g-1 到 1000 mA g-1 的范围内，其容量保持率为 99%。在 100 mA g-1 的电流密度下，该复合阳极可在 500 个循环中提供稳定的比容量 ∼300 mAh g-1。电化学阻抗谱（EIS）研究分析表明，500 次循环后，锂离子扩散速度加快，扩散系数增加了 1000 倍。据我们所知，这是首次对二氧化硅/碳复合材料作为 LIB 负极进行死后研究。包括 XRD、傅立叶变换红外光谱和 SEM 在内的循环后特性分析表明，在长时间循环后，该材料不存在任何杂质相，体积膨胀也可以忽略不计。这进一步证实了二氧化硅/碳复合材料中存在的碳有助于适应二氧化硅的体积膨胀，防止阳极在 500 次循环后出现裂纹。
{"title":"Post-mortem study and long cycling stability of silica/carbon composite as anode in Li-ion cells","authors":"Vaibhavi Gulavani, Musthafa Ottakam Thotiyl, Bibin John and Ashish Yengantiwar","doi":"10.1088/1361-6463/ad5b6f","DOIUrl":"https://doi.org/10.1088/1361-6463/ad5b6f","url":null,"abstract":"The present work emphases on the post-mortem study of silica/carbon composite as functional anode in Li-ion batteries (LIBs). Herein, the silica/carbon composite is synthesized by facile in-situ hydrothermal technique. The x-ray diffraction (XRD) pattern indicates the amorphous nature of silica/carbon composite. The stacked sheet-like morphology of silica/carbon composite is seen in the high-resolution transmission electron microscopy (HR-TEM) & scanning electron microscopy (SEM) images. In addition, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, energy dispersive x-ray analysis (EDAX), and x-ray photoelectron spectra (XPS) characterizations of silica/carbon composite has been studied in detail. The rate capability of silica/carbon composite anode in LIB indicates 99% capacity retention after applying current density ranging from 50 mA g−1 to 1000 mA g−1, successively. The composite anode delivers a stable specific capacity ∼300 mAh g−1 at a current density of 100 mA g−1 for 500 cycles. Electrochemical impedance spectroscopy (EIS) study analyzed the faster Li-ion diffusion and increment in the diffusion coefficient by a factor of 1000 after 500 cycles. To the best of our knowledge, this is the first work on the post-mortem study of silica/carbon composite as anode in LIB. Post-cycling characterizations including XRD, FTIR, and SEM reveal the absence of any impurity phases and negligible volumetric expansion after prolonged cycling. It further confirms that the carbon present in the silica/carbon composite helps to accommodate the volumetric expansion of silica and prevents cracking of the anode over 500 cycles.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"39 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141743363","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 : 2024-07-17DOI: 10.1088/1361-6463/ad60da
Ning Zhang and Hengyi Xu
Ferromagnetic insulators may exhibit magnon Hall effects when subjected to a temperature gradient due to the Dzyaloshinsky–Moriya interaction. In this study, we investigate the magnon thermal Hall conductivity of kagome ferromagnets in real space using the kernel polynomial method. We first establish the formalism in real space within the framework of linear response theory, which enables efficient numerical calculations of thermal transport properties under various imperfections. The validity and accuracy of the real-space approach are confirmed by comparing the calculations with those obtained in momentum space. This approach is particularly advantageous for computing the thermal transport coefficients of disordered lattices. We consider two types of disorder in kagome ferromagnets and observe that both types significantly influence across the entire temperature range. This is in contrast to the effects of strains, where strains primarily impact the maximum values of .
{"title":"Real-space calculation of thermal Hall effects in strained and disordered kagome ferromagnets","authors":"Ning Zhang and Hengyi Xu","doi":"10.1088/1361-6463/ad60da","DOIUrl":"https://doi.org/10.1088/1361-6463/ad60da","url":null,"abstract":"Ferromagnetic insulators may exhibit magnon Hall effects when subjected to a temperature gradient due to the Dzyaloshinsky–Moriya interaction. In this study, we investigate the magnon thermal Hall conductivity of kagome ferromagnets in real space using the kernel polynomial method. We first establish the formalism in real space within the framework of linear response theory, which enables efficient numerical calculations of thermal transport properties under various imperfections. The validity and accuracy of the real-space approach are confirmed by comparing the calculations with those obtained in momentum space. This approach is particularly advantageous for computing the thermal transport coefficients of disordered lattices. We consider two types of disorder in kagome ferromagnets and observe that both types significantly influence across the entire temperature range. This is in contrast to the effects of strains, where strains primarily impact the maximum values of .","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"90 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141743364","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 : 2024-07-16DOI: 10.1088/1361-6463/ad60d9
Zifeng Wang, Xiangyu Wang, Shenghang Xu, Dingxin Liu, Jingyao Zhang, Qiuyi Yue, Luge Wang, Pengfei Zhang, Yikang Jia, Jishen Zhang, Li Guo, Dandan Pei, Chang Liu and Mingzhe Rong
Plasma-activated water (PAW) has broad prospects in the medical field because it is rich in reactive nitrogen and oxygen species. However, in most production processes of PAW, a large proportion of gaseous reactive species is converted into long-lived aqueous species with minor biochemical activity, and only a small proportion is converted into crucial short-lived aqueous species, which results in inefficient activation of PAW. Given the indispensability and easy availability of long-lived aqueous species, this study proposes to preload HNO3 and H2O2 into water and then generate plasma to induce short-lived aqueous species, thus improving the production rate of PAW. The addition of 1 mM HNO3 and 0.5% H2O2 results in a 100-fold increase in the production rate of the PAW with a bactericidal rate exceeding 99.9999%, and the preloaded HNO3 and H2O2 promote the dissolution of O3 and the generation of short-lived aqueous species, respectively. Moreover, the preloaded species improve the validity period of PAW and the resistance of sterilization to acid-base neutralizers. This study offers a novel approach for upgrading the production of PAW, which holds promise for realizing rapid PAW production with a portable device for clinical medical applications.
{"title":"Upgrading the production of plasma-activated water for sterilization by preloading long-lived reactive species","authors":"Zifeng Wang, Xiangyu Wang, Shenghang Xu, Dingxin Liu, Jingyao Zhang, Qiuyi Yue, Luge Wang, Pengfei Zhang, Yikang Jia, Jishen Zhang, Li Guo, Dandan Pei, Chang Liu and Mingzhe Rong","doi":"10.1088/1361-6463/ad60d9","DOIUrl":"https://doi.org/10.1088/1361-6463/ad60d9","url":null,"abstract":"Plasma-activated water (PAW) has broad prospects in the medical field because it is rich in reactive nitrogen and oxygen species. However, in most production processes of PAW, a large proportion of gaseous reactive species is converted into long-lived aqueous species with minor biochemical activity, and only a small proportion is converted into crucial short-lived aqueous species, which results in inefficient activation of PAW. Given the indispensability and easy availability of long-lived aqueous species, this study proposes to preload HNO3 and H2O2 into water and then generate plasma to induce short-lived aqueous species, thus improving the production rate of PAW. The addition of 1 mM HNO3 and 0.5% H2O2 results in a 100-fold increase in the production rate of the PAW with a bactericidal rate exceeding 99.9999%, and the preloaded HNO3 and H2O2 promote the dissolution of O3 and the generation of short-lived aqueous species, respectively. Moreover, the preloaded species improve the validity period of PAW and the resistance of sterilization to acid-base neutralizers. This study offers a novel approach for upgrading the production of PAW, which holds promise for realizing rapid PAW production with a portable device for clinical medical applications.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"27 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717609","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 : 2024-07-11DOI: 10.1088/1361-6463/ad5c6f
R Mata, A Cros, B Gimeno and D Raboso
The recent high demand of secondary electron emission yield (SEY) measurements in dielectric materials from space industry has driven SEY laboratories to improve their facilities and measurement techniques. SEY determination by the common capacitive method, also known as pulsed method, is well accepted and has given satisfactory results in most cases. Nevertheless, the samples under study must be prepared according to the experimental limitations of the technique, i.e. they should be manufactured separated from the devices representing faithfully the surface state of the own device and be as thin as possible. A method based on the Kelvin probe (KP) is proposed here to obtain the SEY characteristics of electrically floating Platinum, Kapton and Teflon placed over dielectric spacers with thicknesses ranging from 1.6 to 12.1 mm. The results are compared with those of the capacitive method and indicate that KP SEY curves are less sensitive to spacer thickness. An explanation based on the literature is also given. In all, we have established that KP is better suited for the analysis of dielectric samples thicker than 3 mm.
{"title":"Secondary electron emission yield in thick dielectric materials: a comparison between Kelvin probe and capacitive methods","authors":"R Mata, A Cros, B Gimeno and D Raboso","doi":"10.1088/1361-6463/ad5c6f","DOIUrl":"https://doi.org/10.1088/1361-6463/ad5c6f","url":null,"abstract":"The recent high demand of secondary electron emission yield (SEY) measurements in dielectric materials from space industry has driven SEY laboratories to improve their facilities and measurement techniques. SEY determination by the common capacitive method, also known as pulsed method, is well accepted and has given satisfactory results in most cases. Nevertheless, the samples under study must be prepared according to the experimental limitations of the technique, i.e. they should be manufactured separated from the devices representing faithfully the surface state of the own device and be as thin as possible. A method based on the Kelvin probe (KP) is proposed here to obtain the SEY characteristics of electrically floating Platinum, Kapton and Teflon placed over dielectric spacers with thicknesses ranging from 1.6 to 12.1 mm. The results are compared with those of the capacitive method and indicate that KP SEY curves are less sensitive to spacer thickness. An explanation based on the literature is also given. In all, we have established that KP is better suited for the analysis of dielectric samples thicker than 3 mm.","PeriodicalId":16789,"journal":{"name":"Journal of Physics D: Applied Physics","volume":"1 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141614875","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}
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