Anita Kumari, Vasu Dev, Tina M. Hayward, Rajesh Menon, Vishwa Pal
We present a novel method for generating optical vortex needle beams (focused optical vortices with extended depth-of-focus) using a compact flat multilevel diffractive lens (MDL). Our experiments demonstrate that the MDL can produce focused optical vortices (FOVs) with topological charges l=1−4 (extendable to other l values), maintaining focus over distances significantly longer than conventional optical vortices. Specifically, FOVs exhibit non-diffracting behavior with a depth-of-focus (DOF) extended beyond 5 cm, compared to conventional optical vortices, which show continuous size increase due to diffraction. When the MDL is illuminated by an optical vortex of 3 mm diameter, it achieves a transmission efficiency of approximately 90% and extends the DOF several times beyond that of traditional lenses. Increasing the size of the input optical vortex further extends the DOF but introduces additional rings, with their number increasing proportionally to the value of l. Our approach, validated by both experimental results and numerical simulations, proves effective for beams such as optical vortex and Hermite-Gaussian modes and holds potential applications in high-resolution imaging, material processing, optical coherence tomography, and three-dimensional optical tweezers, offering a simple and efficient solution for generating non-diffracting beams.
{"title":"Generating optical vortex needle beams with a flat diffractive lens","authors":"Anita Kumari, Vasu Dev, Tina M. Hayward, Rajesh Menon, Vishwa Pal","doi":"10.1063/5.0226316","DOIUrl":"https://doi.org/10.1063/5.0226316","url":null,"abstract":"We present a novel method for generating optical vortex needle beams (focused optical vortices with extended depth-of-focus) using a compact flat multilevel diffractive lens (MDL). Our experiments demonstrate that the MDL can produce focused optical vortices (FOVs) with topological charges l=1−4 (extendable to other l values), maintaining focus over distances significantly longer than conventional optical vortices. Specifically, FOVs exhibit non-diffracting behavior with a depth-of-focus (DOF) extended beyond 5 cm, compared to conventional optical vortices, which show continuous size increase due to diffraction. When the MDL is illuminated by an optical vortex of 3 mm diameter, it achieves a transmission efficiency of approximately 90% and extends the DOF several times beyond that of traditional lenses. Increasing the size of the input optical vortex further extends the DOF but introduces additional rings, with their number increasing proportionally to the value of l. Our approach, validated by both experimental results and numerical simulations, proves effective for beams such as optical vortex and Hermite-Gaussian modes and holds potential applications in high-resolution imaging, material processing, optical coherence tomography, and three-dimensional optical tweezers, offering a simple and efficient solution for generating non-diffracting beams.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"41 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260281","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 relaxor ferroelectric crystal Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT), located near the morphotropic phase boundary (MPB), exhibits exceptionally high piezoelectric and electro-optic (EO) responses. Nevertheless, lower optical transparency and phase transition temperature of PMN-PT limit its optical applications. The ternary system Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) holds promise in addressing these challenges with a higher Curie temperature. Additionally, specific ferroelectric domain polarization techniques can eliminate domain scattering, substantially enhancing the transparency of the crystal. In this study, we explore the optical properties of Sm-doped PIN-PMN-PT. We achieve a 2R domain-engineered state by polarizing along the (110) direction of the crystal. The high transparency allows us to extract an effective EO coefficient of up to 431.5 pm/V from the Sm-PIN-PMN-PT crystal at the telecommunications wavelength. Second-harmonic generation (SHG) probing verified the domain-engineered state in Sm-PIN-PMN-PT. The temperature-dependent SHG reveals the ferroelectric phase transition process, laying the groundwork for studying the stability of the EO response. The Sm-PIN-PMN-PT crystal exhibits an exceptionally high EO coefficient, which is crucial for the development of enhanced EO devices with high integration and low driving voltages.
位于各向形态相边界（MPB）附近的弛豫铁电晶体 Pb（Mg1/3Nb2/3）O3-xPbTiO3（PMN-PT）具有极高的压电和电光（EO）响应。然而，PMN-PT 较低的光学透明度和相变温度限制了其光学应用。三元系统 Pb（In1/2Nb1/2）O3-Pb（Mg1/3Nb2/3）O3-PbTiO3（PIN-PMN-PT）的居里温度较高，有望解决这些难题。此外，特定的铁电畴极化技术可以消除畴散射，大大提高晶体的透明度。在本研究中，我们探索了掺杂 Sm 的 PIN-PMN-PT 的光学特性。我们通过沿晶体的（110）方向极化，实现了 2R 畴工程状态。高透明度使我们能够在电信波长下从 Sm-PIN-PMN-PT 晶体中提取出高达 431.5 pm/V 的有效 EO 系数。二次谐波发生（SHG）探测验证了 Sm-PIN-PMN-PT 中的畴工程状态。随温度变化的 SHG 揭示了铁电相变过程，为研究 EO 响应的稳定性奠定了基础。Sm-PIN-PMN-PT 晶体具有极高的环氧乙烷系数，这对于开发高集成度和低驱动电压的增强型环氧乙烷器件至关重要。
{"title":"Giant electro-optic response in transparent rhombohedral ferroelectric Sm-PIN-PMN-PT crystal based on domain engineering","authors":"Yiyang Wen, Hongda Ren, Xiaona Du, Yang Zhang","doi":"10.1063/5.0230598","DOIUrl":"https://doi.org/10.1063/5.0230598","url":null,"abstract":"The relaxor ferroelectric crystal Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT), located near the morphotropic phase boundary (MPB), exhibits exceptionally high piezoelectric and electro-optic (EO) responses. Nevertheless, lower optical transparency and phase transition temperature of PMN-PT limit its optical applications. The ternary system Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) holds promise in addressing these challenges with a higher Curie temperature. Additionally, specific ferroelectric domain polarization techniques can eliminate domain scattering, substantially enhancing the transparency of the crystal. In this study, we explore the optical properties of Sm-doped PIN-PMN-PT. We achieve a 2R domain-engineered state by polarizing along the (110) direction of the crystal. The high transparency allows us to extract an effective EO coefficient of up to 431.5 pm/V from the Sm-PIN-PMN-PT crystal at the telecommunications wavelength. Second-harmonic generation (SHG) probing verified the domain-engineered state in Sm-PIN-PMN-PT. The temperature-dependent SHG reveals the ferroelectric phase transition process, laying the groundwork for studying the stability of the EO response. The Sm-PIN-PMN-PT crystal exhibits an exceptionally high EO coefficient, which is crucial for the development of enhanced EO devices with high integration and low driving voltages.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"18 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260282","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}
A. V. Myasoedov, M. G. Mynbaeva, S. P. Lebedev, S. Iu. Priobrazhenskii, D. G. Amelchuk, D. A. Kirilenko, A. A. Lebedev
At present, intensive research is underway in the field of vacuum-sublimation growth of 3C-SiC. Transfer of a thin (001)3C-SiC layer onto a 6H-SiC wafer is a promising way to fabricate a 3C-SiC/6H-SiC substrate for growing device-quality homoepitaxial films of low defect density. The article presents the results of the structural characterization of an interface formed during the transfer of a 3C-SiC layer onto a 6H-SiC(0001) wafer, performed with transmission electron microscopy (TEM). A 3C-SiC film with a thickness of about 10 μm, grown by chemical vapor deposition (CVD) on a Si(001) substrate, was utilized in the study. Silicon acted as a bonding material in the transfer process. The morphology and microstructure of the interface between a 6H-SiC substrate and a 3C-SiC (001)-oriented layer are under consideration. TEM investigation reveals an effect of “self”-orientation of the layer with respect to the wafer during the transfer process: an interaction between the molten silicon layer and silicon carbide throughout crystallization results in the generation of defined orientation relationships with respect to substrate axes. An analysis of selected area electron diffraction patterns taken from interfaces showed the relationships to be 3C-SiC{001}‖ 6H-SiC(0001) and 3C-SiC⟨11¯0⟩∼‖ 6H-SiC⟨112¯0⟩.
{"title":"TEM investigation of the interface formation during transfer of 3C-SiC(001) layer onto 6H-SiC(0001) wafer","authors":"A. V. Myasoedov, M. G. Mynbaeva, S. P. Lebedev, S. Iu. Priobrazhenskii, D. G. Amelchuk, D. A. Kirilenko, A. A. Lebedev","doi":"10.1063/5.0227316","DOIUrl":"https://doi.org/10.1063/5.0227316","url":null,"abstract":"At present, intensive research is underway in the field of vacuum-sublimation growth of 3C-SiC. Transfer of a thin (001)3C-SiC layer onto a 6H-SiC wafer is a promising way to fabricate a 3C-SiC/6H-SiC substrate for growing device-quality homoepitaxial films of low defect density. The article presents the results of the structural characterization of an interface formed during the transfer of a 3C-SiC layer onto a 6H-SiC(0001) wafer, performed with transmission electron microscopy (TEM). A 3C-SiC film with a thickness of about 10 μm, grown by chemical vapor deposition (CVD) on a Si(001) substrate, was utilized in the study. Silicon acted as a bonding material in the transfer process. The morphology and microstructure of the interface between a 6H-SiC substrate and a 3C-SiC (001)-oriented layer are under consideration. TEM investigation reveals an effect of “self”-orientation of the layer with respect to the wafer during the transfer process: an interaction between the molten silicon layer and silicon carbide throughout crystallization results in the generation of defined orientation relationships with respect to substrate axes. An analysis of selected area electron diffraction patterns taken from interfaces showed the relationships to be 3C-SiC{001}‖ 6H-SiC(0001) and 3C-SiC⟨11¯0⟩∼‖ 6H-SiC⟨112¯0⟩.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"29 9 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260247","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 target surface to be treated in reality is often not smooth and horizontal and may also be in different tilting angles. The treatment of the tilted dielectric surface by the atmospheric pressure plasma jet (APPJ) undoubtedly increases the complexity of surface modification. Therefore, a two-dimensional fluid model is established to reveal the internal mechanism of the interaction between the He APPJ and the tilted dielectric surface by means of numerical simulation. The distribution of the gas flow in a small angular range (0°, 3°, 5°, 8°, 10°, and 15°) is studied. In addition, the effects of the tilt angle on the jet morphology, discharge dynamic properties, and species distribution of the He APPJ are emphatically discussed. It is found that the jet morphology and parameters are no longer symmetrical under the tilted surface. With the increase in the tilt angle, the enhanced electric field in the upper surface region leads to the increase in the ionization rate and electron density here, and also accelerates the propagation speed of the jet to the dielectric surface in the atmospheric environment. Driven by the electric field force, the jet is closer to the dielectric surface, resulting in a decrease in the thickness of the cathode sheath and an increase in the surface charge density in the area to the right of the central axis. The influence of the gas flow structure leads to the shortening of the jet development distance and a decrease in the jet velocity on the upper surface. N and O also form higher fluxes on the upper surface due to the increase in the electron density.
现实中需要处理的目标表面往往不是光滑和水平的，也可能处于不同的倾斜角度。用常压等离子体射流（APPJ）处理倾斜的介质表面无疑增加了表面改性的复杂性。因此，本文建立了一个二维流体模型，通过数值模拟揭示 He APPJ 与倾斜介质表面相互作用的内部机理。研究了气体流在较小角度范围（0°、3°、5°、8°、10°和 15°）内的分布。此外，还重点讨论了倾斜角对 He APPJ 的射流形态、放电动态特性和物种分布的影响。研究发现，在倾斜表面下，射流形态和参数不再对称。随着倾斜角的增大，上表面区域的电场增强导致这里的电离率和电子密度增加，同时也加快了大气环境中射流向介质表面的传播速度。在电场力的驱动下，射流更接近介质表面，导致阴极鞘厚度减小，中心轴右侧区域的表面电荷密度增大。气流结构的影响导致射流发展距离缩短，上表面的射流速度降低。由于电子密度的增加，N 和 O 在上表面也形成了较高的通量。
{"title":"Numerical simulation of He atmospheric pressure plasma jet impinging on the tilted dielectric surface","authors":"Lijun Wang, Huan Zhao, Zhongji Han, Jie Liu","doi":"10.1063/5.0232639","DOIUrl":"https://doi.org/10.1063/5.0232639","url":null,"abstract":"The target surface to be treated in reality is often not smooth and horizontal and may also be in different tilting angles. The treatment of the tilted dielectric surface by the atmospheric pressure plasma jet (APPJ) undoubtedly increases the complexity of surface modification. Therefore, a two-dimensional fluid model is established to reveal the internal mechanism of the interaction between the He APPJ and the tilted dielectric surface by means of numerical simulation. The distribution of the gas flow in a small angular range (0°, 3°, 5°, 8°, 10°, and 15°) is studied. In addition, the effects of the tilt angle on the jet morphology, discharge dynamic properties, and species distribution of the He APPJ are emphatically discussed. It is found that the jet morphology and parameters are no longer symmetrical under the tilted surface. With the increase in the tilt angle, the enhanced electric field in the upper surface region leads to the increase in the ionization rate and electron density here, and also accelerates the propagation speed of the jet to the dielectric surface in the atmospheric environment. Driven by the electric field force, the jet is closer to the dielectric surface, resulting in a decrease in the thickness of the cathode sheath and an increase in the surface charge density in the area to the right of the central axis. The influence of the gas flow structure leads to the shortening of the jet development distance and a decrease in the jet velocity on the upper surface. N and O also form higher fluxes on the upper surface due to the increase in the electron density.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"19 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260242","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}
P. Casolaro, V. Izzo, G. Giusi, N. Wyrsch, A. Aloisio
We investigated the capacitance of a forward-biased silicon pn diode using impedance spectroscopy. Despite extensive research spanning decades, no single model in the literature adequately describes the impedance behavior for bias up to the built-in voltage. By employing the 1N4007 diode as a case study, we analyzed the impedance over a wide frequency range, from 1 Hz to 1 MHz. Our analysis reveals that impedance can be effectively studied by combining two models. In both models, the depletion capacitance is assumed to be an ideal capacitor with a value independent of frequency. One model accounts for diffusion processes, while the other addresses interfacial effects, as well as potential and capacitance distributions across the junction. This approach offers valuable insights into the complex capacitance behavior of pn junctions as a function of the bias voltage. Measurements of depletion and diffusion capacitances, as well as of the diode transit time can be achieved from a set of impedance spectroscopy data.
{"title":"Modeling the diffusion and depletion capacitances of a silicon pn diode in forward bias with impedance spectroscopy","authors":"P. Casolaro, V. Izzo, G. Giusi, N. Wyrsch, A. Aloisio","doi":"10.1063/5.0230008","DOIUrl":"https://doi.org/10.1063/5.0230008","url":null,"abstract":"We investigated the capacitance of a forward-biased silicon pn diode using impedance spectroscopy. Despite extensive research spanning decades, no single model in the literature adequately describes the impedance behavior for bias up to the built-in voltage. By employing the 1N4007 diode as a case study, we analyzed the impedance over a wide frequency range, from 1 Hz to 1 MHz. Our analysis reveals that impedance can be effectively studied by combining two models. In both models, the depletion capacitance is assumed to be an ideal capacitor with a value independent of frequency. One model accounts for diffusion processes, while the other addresses interfacial effects, as well as potential and capacitance distributions across the junction. This approach offers valuable insights into the complex capacitance behavior of pn junctions as a function of the bias voltage. Measurements of depletion and diffusion capacitances, as well as of the diode transit time can be achieved from a set of impedance spectroscopy data.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"215 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260245","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}
One of the most important issues related to the strength of metals is the strain rate sensitivity of the flow stress. In this study, an analytical model of the flow stress as a function of strain rate is derived theoretically. The model can reproduce the strain rate sensitivity of the flow stress of copper over a wide range of strain rates (up to 109 s−1) quantitatively. Our theoretical derivations indicate that the strain rate sensitivity of the flow stress, especially that above 103 s−1, is a result of both the variation of the dislocation mobility mechanism with stress and the particular stress dependence of dislocation density but is not a result of each single mechanism. In particular, the stress dependence of the dislocation density and the initial dislocation density are critical to the quantitative relation of the flow stress–strain rate at high strain rate and the strain rate threshold, under which the upturn of the flow stress occurs, respectively. Moreover, experiments with copper of different initial dislocation densities at moderate and high strain rate are performed. The strain rate threshold of the flow stress upturn observed in the experiments grows considerably as initial dislocation density increases, which is in accordance with theoretical prediction by our model.
{"title":"Revisiting the strain rate sensitivity of the flow stress of copper: Theory and experiment","authors":"Songlin Yao, Jidong Yu, Xiaoyang Pei, Kai Guo, Enling Tang, Guiji Wang, Qiang Wu","doi":"10.1063/5.0225090","DOIUrl":"https://doi.org/10.1063/5.0225090","url":null,"abstract":"One of the most important issues related to the strength of metals is the strain rate sensitivity of the flow stress. In this study, an analytical model of the flow stress as a function of strain rate is derived theoretically. The model can reproduce the strain rate sensitivity of the flow stress of copper over a wide range of strain rates (up to 109 s−1) quantitatively. Our theoretical derivations indicate that the strain rate sensitivity of the flow stress, especially that above 103 s−1, is a result of both the variation of the dislocation mobility mechanism with stress and the particular stress dependence of dislocation density but is not a result of each single mechanism. In particular, the stress dependence of the dislocation density and the initial dislocation density are critical to the quantitative relation of the flow stress–strain rate at high strain rate and the strain rate threshold, under which the upturn of the flow stress occurs, respectively. Moreover, experiments with copper of different initial dislocation densities at moderate and high strain rate are performed. The strain rate threshold of the flow stress upturn observed in the experiments grows considerably as initial dislocation density increases, which is in accordance with theoretical prediction by our model.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"1 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260243","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}
O. B. Ball, R. J. Husband, J. D. McHardy, M. I. McMahon, C. Strohm, Z. Konôpková, K. Appel, V. Cerantola, A. L. Coleman, H. Cynn, A. Dwivedi, A. F. Goncharov, H. Graafsma, L. Q. Huston, H. Hwang, J. Kaa, J.-Y. Kim, E. Koemets, T. Laurus, X. Li, H. Marquardt, A. S. J. Méndez, S. Merkel, A. Mondal, G. Morard, V. B. Prakapenka, C. Prescher, T. R. Preston, S. Speziale, S. Stern, B. T. Sturtevant, J. Sztuk-Dambietz, N. Velisavljevic, C.-S. Yoo, U. Zastrau, Zs. Jenei, H. P. Liermann, R. S. McWilliams
X-ray self-heating is a common by-product of X-ray Free Electron Laser (XFEL) techniques that can affect targets, optics, and other irradiated materials. Diagnosis of heating and induced changes in samples may be performed using the x-ray beam itself as a probe. However, the relationship between conditions created by and inferred from x-ray irradiation is unclear and may be highly dependent on the material system under consideration. Here, we report on a simple case study of a titanium foil irradiated, heated, and probed by a MHz XFEL pulse train at 18.1 keV delivered by the European XFEL using measured x-ray diffraction to determine temperature and finite element analysis to interpret the experimental data. We find a complex relationship between apparent temperatures and sample temperature distributions that must be accounted for to adequately interpret the data, including beam averaging effects, multivalued temperatures due to sample phase transitions, and jumps and gaps in the observable temperature near phase transformations. The results have implications for studies employing x-ray probing of systems with large temperature gradients, particularly where these gradients are produced by the beam itself. Finally, this study shows the potential complexity of studying nonlinear sample behavior, such as phase transformations, where biasing effects of temperature gradients can become paramount, precluding clear observation of true transformation conditions.
X 射线自热是 X 射线自由电子激光（XFEL）技术的常见副产品，会影响目标、光学器件和其他辐照材料。可以使用 X 射线束本身作为探针，对样品中的加热和诱导变化进行诊断。然而，X 射线辐照所产生的条件与推断出的条件之间的关系尚不明确，而且可能在很大程度上取决于所考虑的材料系统。在此，我们报告了一个简单的案例研究，即欧洲 XFEL 发射的 18.1 千伏的 MHz XFEL 脉冲串对钛箔进行辐照、加热和探测，利用测量的 X 射线衍射确定温度，并利用有限元分析解释实验数据。我们发现表观温度和样品温度分布之间存在复杂的关系，必须考虑到这些因素才能充分解释数据，包括光束平均效应、样品相变引起的多值温度以及相变附近可观测温度的跳跃和间隙。这些结果对采用 X 射线探测具有较大温度梯度的系统的研究具有重要意义，特别是当这些梯度是由光束本身产生的时候。最后，这项研究显示了研究非线性样品行为（如相变）的潜在复杂性，在这种情况下，温度梯度的偏差效应可能变得至关重要，从而阻碍了对真实转变条件的清晰观测。
{"title":"Measurement bias in self-heating x-ray free electron laser experiments from diffraction studies of phase transformation in titanium","authors":"O. B. Ball, R. J. Husband, J. D. McHardy, M. I. McMahon, C. Strohm, Z. Konôpková, K. Appel, V. Cerantola, A. L. Coleman, H. Cynn, A. Dwivedi, A. F. Goncharov, H. Graafsma, L. Q. Huston, H. Hwang, J. Kaa, J.-Y. Kim, E. Koemets, T. Laurus, X. Li, H. Marquardt, A. S. J. Méndez, S. Merkel, A. Mondal, G. Morard, V. B. Prakapenka, C. Prescher, T. R. Preston, S. Speziale, S. Stern, B. T. Sturtevant, J. Sztuk-Dambietz, N. Velisavljevic, C.-S. Yoo, U. Zastrau, Zs. Jenei, H. P. Liermann, R. S. McWilliams","doi":"10.1063/5.0215908","DOIUrl":"https://doi.org/10.1063/5.0215908","url":null,"abstract":"X-ray self-heating is a common by-product of X-ray Free Electron Laser (XFEL) techniques that can affect targets, optics, and other irradiated materials. Diagnosis of heating and induced changes in samples may be performed using the x-ray beam itself as a probe. However, the relationship between conditions created by and inferred from x-ray irradiation is unclear and may be highly dependent on the material system under consideration. Here, we report on a simple case study of a titanium foil irradiated, heated, and probed by a MHz XFEL pulse train at 18.1 keV delivered by the European XFEL using measured x-ray diffraction to determine temperature and finite element analysis to interpret the experimental data. We find a complex relationship between apparent temperatures and sample temperature distributions that must be accounted for to adequately interpret the data, including beam averaging effects, multivalued temperatures due to sample phase transitions, and jumps and gaps in the observable temperature near phase transformations. The results have implications for studies employing x-ray probing of systems with large temperature gradients, particularly where these gradients are produced by the beam itself. Finally, this study shows the potential complexity of studying nonlinear sample behavior, such as phase transformations, where biasing effects of temperature gradients can become paramount, precluding clear observation of true transformation conditions.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"29 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260249","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 unreacted equation of state (EOS) for an unreacted explosive can provide fundamental information to understand any analytical model for the shock and initiation process. Based on the Hugoniot expression in Jones–Wilkins–Lee (JWL) form derived from the Mie–Grüneisen EOS and conservation equation across the shock wave, a three-point calibrating method to determine the JWL EOS parameters for unreacted explosives was developed using intelligent algorithms and shock Hugoniot relationship of the explosives considered. The calibration method proposed utilizes the back propagation neural network to predict the nonlinear system composed of different JWL parameter sets; the genetic algorithm is then used to find the optimal solution of the JWL parameter set. Unreacted JWL EOS parameters of eight typical explosives were calibrated using the calibrating method developed, and an excellent agreement can be observed between JWL EOS and experimental p–v curves for all eight explosives selected, indicating the high accuracy of the three-point calibrating method. However, the effectiveness of the three-point calibrating method was experimentally validated with the experimental data measured from the shock tests of the dihydroxylammonium 5,5′-bitetrazole-1,1′-dioxide (TKX-50)-based explosive, where the JWL p–v curve derived from the three-point calibrating method is in good agreement with the experimental curve.
未反应炸药的未反应状态方程（EOS）可为理解冲击和起爆过程的任何分析模型提供基本信息。根据从 Mie-Grüneisen EOS 和整个冲击波守恒方程导出的琼斯-威尔金斯-李（JWL）形式的休伊特表达式，利用智能算法和所考虑的爆炸物的冲击休伊特关系，开发了一种三点校准方法，以确定未反应爆炸物的 JWL EOS 参数。所提出的校准方法利用反向传播神经网络预测由不同 JWL 参数集组成的非线性系统，然后利用遗传算法找到 JWL 参数集的最优解。利用所开发的校准方法对八种典型炸药的未反应 JWL EOS 参数进行了校准，结果表明所选八种炸药的 JWL EOS 与实验 p-v 曲线之间具有极好的一致性，表明三点校准法具有很高的准确性。不过，三点校准法的有效性要通过实验验证，实验数据来自 5,5′-二羟基四唑-1,1′-二氧化物（TKX-50）基二羟基铵炸药的冲击试验，三点校准法得出的 JWL p-v 曲线与实验曲线吻合良好。
{"title":"Calibration of Jones–Wilkins–Lee equation of state for unreacted explosives with shock Hugoniot relationship and optimization algorithm","authors":"Hao Cui, Junan Wu, Yuxin Xu, Hao Zhou, Rui Guo","doi":"10.1063/5.0230362","DOIUrl":"https://doi.org/10.1063/5.0230362","url":null,"abstract":"The unreacted equation of state (EOS) for an unreacted explosive can provide fundamental information to understand any analytical model for the shock and initiation process. Based on the Hugoniot expression in Jones–Wilkins–Lee (JWL) form derived from the Mie–Grüneisen EOS and conservation equation across the shock wave, a three-point calibrating method to determine the JWL EOS parameters for unreacted explosives was developed using intelligent algorithms and shock Hugoniot relationship of the explosives considered. The calibration method proposed utilizes the back propagation neural network to predict the nonlinear system composed of different JWL parameter sets; the genetic algorithm is then used to find the optimal solution of the JWL parameter set. Unreacted JWL EOS parameters of eight typical explosives were calibrated using the calibrating method developed, and an excellent agreement can be observed between JWL EOS and experimental p–v curves for all eight explosives selected, indicating the high accuracy of the three-point calibrating method. However, the effectiveness of the three-point calibrating method was experimentally validated with the experimental data measured from the shock tests of the dihydroxylammonium 5,5′-bitetrazole-1,1′-dioxide (TKX-50)-based explosive, where the JWL p–v curve derived from the three-point calibrating method is in good agreement with the experimental curve.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"17 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260239","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}
M. E. García Redondo, N. A. Müller, J. M. Salum, L. P. Ferreyro, J. D. Bonilla-Neira, J. M. Geria, J. J. Bonaparte, T. Muscheid, R. Gartmann, A. Almela, M. R. Hampel, A. E. Fuster, L. E. Ardila-Perez, M. Wegner, M. Platino, O. Sander, S. Kempf, M. Weber
The Microwave SQUID Multiplexer (μMUX) is the device of choice for the readout of a large number of low-temperature detectors in a wide variety of experiments within the fields of astronomy and particle physics. While it offers large multiplexing factors, the system noise performance is highly dependent on the cold- and warm-readout electronic systems used to read it out, as well as the demodulation domain and parameters chosen. In order to understand the impact of the readout systems in the overall detection system noise performance, first, we extended the available μMUX simulation frameworks, including additive and multiplicative noise sources in the probing tones (i.e., phase and amplitude noise), along with the capability of demodulating the scientific data, either in the resonator’s phase or the scattering amplitude. Then, considering the additive noise as a dominant noise source, the optimum readout parameters to achieve minimum system noise were found for both open-loop and flux-ramp demodulation schemes in the aforementioned domains. Later, we evaluated the system noise sensitivity to multiplicative noise sources under the optimum readout parameters. Finally, as a case study, we evaluated the optimal demodulation domain and the expected system noise level for a typical software-defined radio readout system. This work leads to an improved system performance prediction and noise engineering based on the available readout electronics and the selected demodulation domain.
{"title":"Optimal demodulation domain for microwave SQUID multiplexers in presence of readout system noise","authors":"M. E. García Redondo, N. A. Müller, J. M. Salum, L. P. Ferreyro, J. D. Bonilla-Neira, J. M. Geria, J. J. Bonaparte, T. Muscheid, R. Gartmann, A. Almela, M. R. Hampel, A. E. Fuster, L. E. Ardila-Perez, M. Wegner, M. Platino, O. Sander, S. Kempf, M. Weber","doi":"10.1063/5.0222656","DOIUrl":"https://doi.org/10.1063/5.0222656","url":null,"abstract":"The Microwave SQUID Multiplexer (μMUX) is the device of choice for the readout of a large number of low-temperature detectors in a wide variety of experiments within the fields of astronomy and particle physics. While it offers large multiplexing factors, the system noise performance is highly dependent on the cold- and warm-readout electronic systems used to read it out, as well as the demodulation domain and parameters chosen. In order to understand the impact of the readout systems in the overall detection system noise performance, first, we extended the available μMUX simulation frameworks, including additive and multiplicative noise sources in the probing tones (i.e., phase and amplitude noise), along with the capability of demodulating the scientific data, either in the resonator’s phase or the scattering amplitude. Then, considering the additive noise as a dominant noise source, the optimum readout parameters to achieve minimum system noise were found for both open-loop and flux-ramp demodulation schemes in the aforementioned domains. Later, we evaluated the system noise sensitivity to multiplicative noise sources under the optimum readout parameters. Finally, as a case study, we evaluated the optimal demodulation domain and the expected system noise level for a typical software-defined radio readout system. This work leads to an improved system performance prediction and noise engineering based on the available readout electronics and the selected demodulation domain.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"62 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260241","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}
N-type carbon nanotubes (CNTs)-based field-effect transistors (FETs) have huge potential applications in low-power consumption tunnel FETs. However, the low-work function metal electrodes can achieve n-type CNTs, but they are easily oxidized due to poor environmental stability. Therefore, based on first-principles calculations, we proposed halide perovskite nanowires Cs4MX5 (M = Pb, Sn; X = Cl, Br, I) inner filling to achieve n-type single-walled CNTs (SWCNTs). The results indicated that all the perovskite nanowires located at the center of the SWCNTs possess high stability. Moreover, the diameter of SWCNTs is a crucial factor affecting the inner filling of perovskite nanowires with an optimal diameter of about 1.4 nm. Furthermore, all the perovskite nanowires Cs4MX5 are excellent electron donors, and the largest charge transfer is up to 1.72 e/nm for Cs4SnI5. Their interaction mechanism reveals that the low work function and the large internal bandgap are two important factors for cubic-phase nanowires to realize the n-type CNTs. Our findings provide some candidate materials and a feasible way to achieve n-type CNTs for applying CNTs-based FETs.
基于 N 型碳纳米管（CNT）的场效应晶体管（FET）在低功耗隧道 FET 中具有巨大的应用潜力。然而，低功函数金属电极可以实现 N 型 CNT，但由于环境稳定性差，很容易被氧化。因此，我们在第一原理计算的基础上，提出了卤化物包晶纳米线 Cs4MX5（M = Pb、Sn；X = Cl、Br、I）内部填充来实现 n 型单壁 CNT（SWCNT）。结果表明，位于 SWCNT 中心的所有过氧化物纳米线都具有很高的稳定性。此外，SWCNTs 的直径是影响包晶纳米线内部填充的关键因素，其最佳直径约为 1.4 nm。此外，所有的包晶纳米线 Cs4MX5 都是出色的电子供体，其中 Cs4SnI5 的最大电荷转移量高达 1.72 e/nm。它们的相互作用机理揭示了低功函数和大内带隙是立方相纳米线实现 n 型 CNT 的两个重要因素。我们的发现为应用基于 CNTs 的 FET 提供了一些候选材料和实现 n 型 CNTs 的可行方法。
{"title":"Realizing n-type carbon nanotubes via halide perovskite nanowires Cs4MX5 inner filling","authors":"Sisi Cao, Qiyao Yang, Juexian Cao, Wangping Xu","doi":"10.1063/5.0225284","DOIUrl":"https://doi.org/10.1063/5.0225284","url":null,"abstract":"N-type carbon nanotubes (CNTs)-based field-effect transistors (FETs) have huge potential applications in low-power consumption tunnel FETs. However, the low-work function metal electrodes can achieve n-type CNTs, but they are easily oxidized due to poor environmental stability. Therefore, based on first-principles calculations, we proposed halide perovskite nanowires Cs4MX5 (M = Pb, Sn; X = Cl, Br, I) inner filling to achieve n-type single-walled CNTs (SWCNTs). The results indicated that all the perovskite nanowires located at the center of the SWCNTs possess high stability. Moreover, the diameter of SWCNTs is a crucial factor affecting the inner filling of perovskite nanowires with an optimal diameter of about 1.4 nm. Furthermore, all the perovskite nanowires Cs4MX5 are excellent electron donors, and the largest charge transfer is up to 1.72 e/nm for Cs4SnI5. Their interaction mechanism reveals that the low work function and the large internal bandgap are two important factors for cubic-phase nanowires to realize the n-type CNTs. Our findings provide some candidate materials and a feasible way to achieve n-type CNTs for applying CNTs-based FETs.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"10 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260279","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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