bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature evolution of 3d- and 4f-electron magnetic ordering in the ferrimagnetic Mn self-doped perovskite (Yb0.667Mn0.333)MnO3
Authors: Dönni Andreas , Pomjakushin Vladimir Y , Zhang Lei , Yamaura Kazunari , Belik Alexei A 
Published: February 2021

Abstract
A high-pressure synthesis method was employed to prepare Mn-self-doped perovskites (R
0.667Mn0.333)MnO3 (R = Yb, Lu) at about 6 GPa and 1670 K. Crystal and magnetic structures of (Yb0.667Mn0.333)MnO3 have been studied by combining neutron powder diffraction, magnetic susceptibility and specific heat measurements. Within the orthorhombic space group Pnma, magnetic cations are located on site 4c (A site, occupied by two thirds of Yb3+ and one third of Mn2+) and on site 4b (B site, occupied by two thirds of Mn3+ and one third of Mn4+). The degree of structural distortion of the MnO6 octahedra follows the general trend of (R1−x
Mn
x
)MnO3 compounds which shows a decrease with increasing amount of Jahn–Teller inactive Mn4+ cations. Mn–Mn interactions produce a collinear ferrimagnetic structure (T
C,Mn = 106 K) with ferromagnetically ordered Mn moments at the B site being coupled antiferromagnetically with ordered Mn moments at the A site. Mn–Yb interactions induce a small but non-zero ferromagnetic Yb3+ moment which can explain a small decrease of the magnetic susceptibility at low temperature. Yb–Yb interactions create an antiferromagnetic structure at T
N,Yb ≈ 40 K. Ordered moments of the ferrimagnetic and antiferromagnetic structures are oriented perpendicular to each other within the ac-plane and Yb3+ moments contribute to both structures. The appearance of ordered Yb3+ moments induced by Mn–Yb interactions in perovskite (Yb0.667Mn0.333)MnO3 is a result of the Mn self-doping on the A site and has not been observed in the orthorhombic perovskite modification (space group Pnma) of the undoped parent compound YbMnO3, but interestingly, it also appears in the hexagonal non-perovskite modification (space group P63
cm) of YbMnO3.
Improved clearance verification
Authors: Meck Robert A , Jiselmark Jonatan 
Published: February 2021

Abstract
This paper describes clearance as the sum of fractions (SOF) inequality with acceptable probability. We include scenario modelling uncertainties in SOF calculations. An illustrative contrast of results with and without the modelling uncertainties shows the differences in the probabilities that the standards were met. We present two methods for calculations, the analytical approach, GUM, and the Monte Carlo (MC) method. We prefer the MC. Inclusion of the scenario uncertainties can provide improved assurance that people are adequately protected. An example that used data from a Swedish reactor is included.
Uncertainty evaluation in atomic force microscopy measurement of nanoparticles based on statistical mixed model in a Bayesian framework
Authors: Pétry J , Boeck B De , Sebaïhi N , Coenegrachts M , Caebergs T , Dobre M 
Published: February 2021

Abstract
A major bottleneck in nanoparticle sizing is the lack of data comparability between techniques and between laboratories. However, this can be overcome by making the measurements traceable to the SI together with realistic uncertainty evaluation. In the present work, a novel approach is proposed to perform measurement uncertainty evaluation in a Bayesian framework by statistically modeling appropriately selected measurement data when no comprehensive physical model is available. The method is applied to the dimensional measurement of nanoparticles by atomic force microscopy (AFM) measurement and the calibration is performed by a multiple points calibration curve. Nevertheless, the proposed method can be applied to other microscopy techniques. The experimental data used to construct the statistical model are collected so that the influence of relevant measurement parameters can be assessed. An optimized experiment is designed under the intermediate precision conditions in order to limit the number of measurements to perform. Among the different influencing parameters, it is found that the AFM operator and image analyst do not significantly affect the measurement variability while the tip tapping force, the probe nature and the tip scan speed do. The particular case of gold nanoparticle of nominal diameter 30 nm is treated as an example of the method.
Modifying the theoretical model of the target indirect measurement method for measuring the thrust of electric propulsion
Authors: Weng Huiyan , Cai Guobiao , Liu Lihui , Zheng Hongru , Zhang Mingxing , Zhang Baiyi , He Bijiao 
Published: February 2021

Abstract
Electric propulsion systems, such as ion thrusters and Hall thrusters, are widely utilized in aerospace. The target indirect measurement method (TIMM) is a simple and robust way to measure its thrust. In general, one can obtain the thrust by scaling up the force exerted on the target surface immersed in the plume flow. However, the charge exchange (CEX) allows ions to become neutral particles, increasing the scaling coefficient. Meanwhile, the sputtered atoms and reflected incident particles exert force on the target surface and enlarge the measured thrust. In this study, the effects of the CEX, the sputtering, and the reflection on the TIMM are mathematically quantified, and then a modified model of the TIMM is proposed. Besides, the thrusts of the LIPS-200 and LIPS-300 ion thrusters were separately measured using the TIMM with the modified model, and the measured thrusts are in good agreement with the rated thrusts. Under the test conditions, the results of the LIPS-300 ion thruster show that the fast neutral atoms produced by the CEX account for more than 20% of all fast particles impacting on the target, and the force caused by the sputtered atoms is about 3.4% of the total force exerted on the target. We discuss how test conditions affect the CEX, sputtering, and reflection, thereby influencing the TIMM. The modified model was also validated through the simulation results, by showing that the measured thrust cannot be influenced by the test conditions.
A variational fast Fourier transform method for phase-transforming materials
Authors: Cruzado A , Segurado J , Hartl D J , Benzerga A A 
Published: February 2021

Abstract
A fast Fourier transform (FFT) based method is developed to model the pseudo-elastic behavior and shape-memory effect in phase transforming materials. An infinitesimal strain based variational FFT formulation is adapted and enhanced to enable the solution of nonlinear, stress-controlled and thermo-mechanical problems. The capabilities of the method are illustrated by implementing a computational homogenization approach to modeling the thermo-mechanical response of shape memory alloys with heterogeneities. The accuracy and performance of the method is evaluated by comparison with finite element (FE) solutions for single- and multi-particle cells subjected to various loading schemes. For the class of nonlinear problems of interest, the proposed method is shown to be an order of magnitude faster than the FE method for a given resolution, and possibly for the same accuracy.
Highly sensitive nanoparticle sensing based on a hybrid cavity in a freely suspended microfiber
Authors: Cheng Qi , Wang Shutao , Lv Jiangtao , Wang Junzhu , Liu Na 
Published: February 2021

Abstract
We report a hybrid cavity structure based on a suspended microfiber with a diameter of 1.7 μm applied to nanoparticle sensing in water. The proposed hybrid cavity is composed of two symmetrical reflectors with a slotted Au layer in the middle. After being characterized by the finite-difference time-domain method, the obtained strong reflection and sufficiently wide band gap provide the potential to realize an ultrasmall mode volume, which can improve sensitivity and lower loss. In addition, an ultrahigh Q/V ratio of 8.2 × 106 (λ/n)−3 and high resonance transmittance of T = 0.53 can be obtained through optimization analysis. After analyzing the trapping force and resonance shift caused by the change in local electric field, it is proven that our proposed cavity exhibits a high sensitivity and offers a convenient and stable method for particle sensing in water.
Magnetically responsive polymer nanopillars with nickel cap
Authors: Luo Zhiren , Zhang Xu A , Chang Chih-Hao 
Published: February 2021

Abstract
Embedding magnetic particles within polymer matrix is a common and facile method to fabricate magnetically responsive micro-/nanoscale pillars. However, the balance between mechanical compliance and magnetic susceptibility cannot be decoupled and the particles are limited by the pillar feature size, which can limit the actuation performance. Here we demonstrate a new type of magnetically responsive nanostructure consisting of a polydimethylsiloxane (PDMS) nanopillar array with deposited nickel caps, that has successfully achieved such decoupling with multiple cap-geometry designs for a better actuation control. The actuation result of nanopillars with 540 nm period and 1.3 μm height has been analyzed using image processing, leading to a maximum displacement of 180 nm with a ratio of 13.9% with respect to the pillar height. Magnetic and mechanical models based on magnetic force and torque have been developed and used to mitigate the weakening effect of the actuation by the residual magnetic layer. This structure demonstrates a feasible strategy for magnetic actuation at the sub-micrometer scale with freedom to design magnetic cap and polymeric pillar separately. This structure can also be utilized in multiple applications such as tunable optical elements, dynamic droplet manipulation, and responsive particle manipulation.
A minimally invasive electrostatic particle extractor for nanodusty plasmas and its application for the verification of in situ Mie polarimetry
Authors: Dworschak Maren , Asnaz Oguz Han , Greiner Franko 
Published: February 2021

Abstract
We present an electrostatic particle extractor system (EPEX) which extracts particles from a reactive, particle-growing plasma by using the electrostatic force. The system is able to extract eight samples during a single growth cycle without the need to interrupt the plasma process. Using video microscopy, imaging-Mie, and Mie polarimetry we demonstrate the minimal invasiveness of EPEX. The extraction voltage and its duration are optimized to tune the particle density on the sample wafer. Compared to other invasive extraction methods, EPEX is fast and reliable. Using atomic force microscopy the size of the particles can be determined from samples extracted from the nanodusty plasma during one growth cycle and can be compared to the results of simultaneously performed in situ Mie polarimetry for the first time. We show that the extraction process can be divided in three distinct phases and that its physics can be understood in the simple framework of the force balance for a single dust particle. Using this single particle model, we present a new method for determining the particle charge of dust particles in dense dusty plasmas. The determined particle charge of (−9.2 ± 2.8) elementary charges reveals a strong Havnes effect.
Continuum level-set model for anisotropic wet etching of patterned sapphire substrates
Authors: Toifl A , Rodrigues F , Aguinsky L F , Hössinger A , Weinbub J 
Published: February 2021

Abstract
We present a continuum modeling approach to simulate anisotropic wet etching of single-crystal sapphire employing mixtures of sulfuric acid and phosphoric acid. Wet etching of sapphire leads to the formation of crystal facets with high Miller–Bravais indices. The resulting complex three-dimensional topographies can be exploited to optimize the patterning of sapphire substrates which are employed for gallium nitride based light-emitting diodes. Due to the strong impact of the three-dimensional sapphire topography on the light extraction efficiency of the final device, precise control over the wet etching process, in particular etchant mixture, etch time, and temperature, is highly important. We present our model in the context of process technology computer-aided design, where we use the level-set method to track the evolution of the three-dimensional etch profile over time. In order to describe the intricate anisotropy of wet etched sapphire, we propose a flexible interpolation method for the etch rate distribution, which incorporates experimentally characterized crystal facets and deduces local extrema in the distribution based on local convexity/concavity considerations. The developed model has been calibrated and evaluated based on scanning electron microscopy and atomic force microscopy characterizations from the literature. Our model enables accurate sapphire etching simulations, where the emerging and disappearing crystal facets show a good agreement with experimental observations for several etchant mixtures and temperatures.
Influence of Al content on ZnO/Al bilayer-structure ultraviolet photodetector
Authors: Si Jiawei , Song Wenqing , Wang Liancheng , Zhu Wenhui , Zhang Lei 
Published: February 2021

Abstract
As a potential optoelectronic material, the use of ZnO in ultraviolet (UV) photodetectors is attracting significant attention. In this study, aluminum (Al) nanoparticles of different content and ZnO films are sequentially sputtered to form ZnO/Al bilayer UV photodetectors. The responsivity of the ZnO/Al bilayer photodetector, with a maximum of 380.9 A W−1 at 320 nm and 5 V bias, is higher than that of the single-layer ZnO photodetector. The enhanced responsivity of the ZnO/Al bilayer UV photodetectors can be attributed to the local surface plasmon resonance effect and the introduction of oxygen vacancies. Meanwhile, the different size and distribution density of Al nanoparticles determines the different enhanced mechanisms. Our work provides a promising route to design and fabricate a high-performance photodetector.
Damage detection in large composite stiffened panels based on a novel SHM building block philosophy
Authors: Yue Nan , Khodaei Zahra Sharif , Aliabadi M H 
Published: February 2021

Abstract
This paper proposes a structural health monitoring (SHM) building block (BB) approach for guided wave based structural health monitoring (GWSHM) of large composite stiffened panel subjected to varying temperature conditions. The proposed approach follows a similar philosophy to industrial substantiation of composite structures through BB by conducting SHM analysis and associated tests at different levels of structural complexity, beginning with small coupon specimens and progressing through structural elements and details (mono-stringer) and finally sub-components (large stiffened composited panel). Each level builds on the knowledge gained at previous, less complex levels. The detection of multiple barely visible impact damage (BVID) in the large panels is achieved by outlier analysis using a reference pristine database gathered from simple coupons and mono-stringer panels under a wide range of temperature variation. This approach enables the data utilisation from lower-level structure in the proposed BB test scheme to higher-level structures and hence reduce the number of tests required for large and complex structures. The detected damage is then localised by a proposed two-step multi-damage localisation method, which first confirms the presence of the damage and narrows down the damaged section then provides an enhanced damage imaging for precise location estimation. Damage detection with a true positive rate of 0.909 and a false positive rate of 0.111 as well as accurate multiple damage localisation are achieved in the flat fuselage panels for a temperature range of 25 °C–50 °C.
Multi-photon resonances in Josephson junction-cavity circuits
Authors: Lang Ben , Armour Andrew D 
Published: February 2021

Abstract
We explore the dissipative dynamics of nonlinearly driven oscillator systems tuned to resonances where multiple excitations are generated. Such systems are readily realised in circuit QED systems combining Josephson junctions with a microwave cavity and a drive achieved either through flux or voltage bias. For resonances involving three or more photons the system undergoes a sequence of two closely spaced dynamical transitions (the first one discontinuous and the second continuous) as the driving is increased leading to steady states that form complex periodic structures in phase space. In the vicinity of the transitions the system displays interesting bistable behaviour: we find that coherent effects can lead to surprising oscillations in the weight of the different dynamical states in the steady state of the system with increasing drive. We show that the dynamics is well-described by a simple effective rate model with transitions between states localised at different points in the phase space crystal. The oscillations in the weights of the dynamical states is reflected in corresponding oscillations in a time-scale that describes transitions between the states.
Theoretical investigations on HgTe chalcogenide materials under high pressure
Authors: Duz I , Kart H H , Ozdemir Kart S , Kuzucu V 
Published: February 2021

Abstract
First principle computations based on Density Functional Theory are made to investigate structural, mechanical, electronic properties and phase transition behaviors of HgTe chalcogenide material. It is obtained that the phase transition sequence of HgTe material is Zincblende → Cinnabar → Rocksalt → Cmcm → CsCl at 2.35 GPa, 5.95 GPa, 14.29 GPa, 52.37 GPa, respectively. The negative

C

44

and

C

s

values of the CsCl structure under ambient conditions indicate that this structure is mechanically unstable against the applied deformations. The small values of the elastic constants of HgTe in the cinnabar structure reveal that this structure is less resistant to deformations. The low value of tetragonal shear constant Cs of the parent phase reflects the elastic instability leading to a pressure-induced phase transition. According to our isotropic mechanical results obtained from the Voigt-Reuss-Hill (VRH) approach, the ductility behavior improves in the rocksalt and Cmcm structures which are high-pressure phases. The zincblende and cinnabar structures show semimetal and semiconductor properties in the electronic band calculations, respectively, while rocksalt, Cmcm and CsCl structures are found to be of metallic character.
The upgraded ASDEX Upgrade contribution to the ITPA confinement database: description and analysis
Authors: Ryter F. , Angioni C. , Tardini G. , Birkenmeier G. , David P. , Dunne M. , Fischer R. , Pütterich T. , Schweinzer J. , Stober J. , ASDEX Upgrade Team The , EUROfusion MST1 Team The 
Published: February 2021

Abstract
The ITPA multi-machine confinement database has been recently extended, in particular to account for the effect of the metallic plasma facing components installed in the ASDEX Upgrade and JET tokamaks during the last decade. Confinement data from the ASDEX Upgrade tokamak have been contributed to the ITPA confinement database since 1994. The present version, which includes data from 1994 to 2017, is described and discussed in this article. The aim of this work is to document the database before it is made public and report on the main results on the confinement properties reflected in this database. Through the transition from carbon to metallic wall, the operation at low density originally accessible with the carbon wall, has been strongly limited by the occurrence of tungsten accumulation. However, at medium and high densities, the confinement properties with the carbon and metallic walls are rather similar. The database analysis yields in both cases a rather strong plasma current dependence and a clearly negative magnetic field dependence. The density dependence is negligible, while the well-known positive impact of triangularity appears very clearly. These dependences are partly at variance with the widely-used IPB98(y,2) confinement scaling, but in agreement with the analysis of the upgraded ITPA multi-machine and JET databases. The confinement degradation observed at high density with strong gas puffing can be clearly attributed to the density profile in the outer plasma region, as reported in previous studies.
Observation of TAE mode driven by off-axis ECRH induced barely trapped energetic electrons in EAST tokamak
Authors: Chu N. , Sun Y. , Shen B. , Hu Y.J. , Gu S. , Jia M. , Wang H.H. , Shi T.H. , Bao J. , Duan Y.M. , He K.Y. , Li E. , Liu H.Q. , Liu Y. , Lyu B. , Ma Q. , Qian J.P. , Ren J. , Ti A. , Wang H.L. , Wang S.X. , Wang X.J. , Wang Y.M. , Zang Q. , Zeng L. , Zhang J.Z. , Zhang T. , Zhang Y. , Zhao H.L. , Zhou R.J. , Zhou T.F. 
Published: February 2021

Abstract
A toroidal Alfvén eigenmode (TAE) is excited by electron cyclotron resonance heating (ECRH) induced barely trapped energetic electrons in experimental advanced superconducting tokamak . This TAE appears in the low density EAST discharges under pure off-axis ECRH heating. After analysing the ECRH power modulation induced local density and temperature oscillations, the location of this TAE mode and the power deposition of ECRH are determined. This edge localized TAE mode drifts in ion-diamagnetic direction may be driven by barely trapped energetic electrons considering the contribution of poloidal bounce effect in the general wave-particle resonance condition. The experimental observations also demonstrate that ECRH power modulation with fixed frequency could be used as an effective diagnostic tool to study the internal properties of MHD modes as well as particle and heat transports.
Numerical investigation of alpha particle confinement under the perturbation of neoclassical tearing modes and toroidal field ripple in CFETR
Authors: Hao Baolong , White Roscoe , Gao Xiang , Li Guoqiang , Chen Wei , Wang Xiaojing , Wu Bin , Wu Muquan , Zhu Xiang , Lin Xiaodong , Jie Yinxian , Zang Qing , Li Jiangang , Wan Yuanxi , Physics Team CFETR 
Published: February 2021

Abstract
The confinement of alpha particles in burning plasma is a key issue in fusion reactor design, including particle interaction with instabilities. This paper includes two topics: the effect of neoclassical tearing modes (NTMs) and toroidal field ripple on alpha particle loss, and the assessment of particle redistribution under an NTM with a reduced model. We consider Chinese fusion engineering test reactor parameters, the alpha particle distribution given by TRANSP/NUBEAM and the NTM perturbation function given by the initial value code TM1. We show that the synergistic effect of the NTM and ripple is negligible; the particle loss fraction does not change with increasing NTM amplitude. Only passing particles are affected by the mode particle resonance, producing profile flattening but no increased loss because only trapped particles are influenced by ripple. To study alpha particle profile flattening, the work adopts an innovative method of phase vector rotation to determine regions of good and broken Kolmogorov–Arnold–Moser surfaces and equilibrates the particle density according to local stochasticity.