scholarly journals Large-scale multiferroic complex oxide epitaxy with magnetically switched polarization enabled by solution processing

2019 ◽  
Vol 7 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Cong Liu ◽  
Feng An ◽  
Paria S M Gharavi ◽  
Qinwen Lu ◽  
Junkun Zha ◽  
...  
Keyword(s):  
Large Scale ◽  
Room Temperature ◽  
Complex Oxide ◽  
Industrial Applications ◽  
Atomic Scale ◽  
Solution Processing ◽  
Large Area ◽  
Bulk Magnetization ◽  
Magnetoelectric Coefficient ◽  
Film Making

Abstract Complex oxides with tunable structures have many fascinating properties, though high-quality complex oxide epitaxy with precisely controlled composition is still out of reach. Here we have successfully developed solution-based single-crystalline epitaxy for multiferroic (1-x)BiTi(1-y)/2FeyMg(1-y)/2O3–(x)CaTiO3 (BTFM–CTO) solid solution in large area, confirming its ferroelectricity at the atomic scale with strong spontaneous polarization. Careful compositional tuning leads to a bulk magnetization of 0.07 ± 0.035 μB/Fe at room temperature, enabling magnetically induced polarization switching exhibiting a large magnetoelectric coefficient of 2.7–3.0 × 10−7 s/m. This work demonstrates the great potential of solution processing in large-scale complex oxide epitaxy and establishes novel room-temperature magnetoelectric coupling in epitaxial BTFM–CTO film, making it possible to explore a much wider space of composition, phase, and structure that can be easily scaled up for industrial applications.

Thermal Effects on the Friction of Sliding Rough Surfaces

2011 ◽  
Author(s):  
Peter Spijker ◽  
Guillaume Anciaux ◽  
Jean-Franc¸ois Molinari
Keyword(s):  
Molecular Dynamics ◽  
Thermal Effects ◽  
Large Scale ◽  
Room Temperature ◽  
Applied Load ◽  
Close Contact ◽  
Rough Surfaces ◽  
Md Simulations ◽  
Atomic Scale ◽  
Deformable Bodies

We use large-scale molecular dynamics (MD) simulations to model the sliding of deformable bodies in close contact, where both bodies have self-affine rough surfaces at the atomistic level. We keep both bodies at room temperature, while changing the surface roughness and the applied load. We compared our current results with similar cases at zero Kelvin and find surprisingly that a mild thermal increase from 0 to 300 K of the material enhances friction at the atomic scale.

Epitaxial growth and room-temperature ferromagnetism of quasi-2D layered Cr4Te5thin film

2022 ◽  
Author(s):  
Jing Wang ◽  
Weiyuan Wang ◽  
Jiyu Fan ◽  
Huan Zheng ◽  
Hao Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Large Scale ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Room Temperature Ferromagnetism ◽  
Magnetic Interactions ◽  
Large Area ◽  
Easy Magnetization ◽  
Mean Field Model

Abstract Large-scale growth of two-dimensional (2D) ferromagnetic thin films will provide an ideal platform for studying 2D magnetism and active spintronic devices. However, controllable growth of 2D ferromagnets over large areas faces tremendous challenges. Herein, we report a large-area growth of 2D ferromagnetic single-crystal thin films Cr4Te5 on Al2O3 (0001) substrates using pulsed laser deposition. X-ray diffraction patterns and atomic force microscopy detection confirm that all thin films are high quality epitaxy together with atom-level smooth. Magnetic measurements show the persistence of ferromagnetic ordering state up to above room temperature, with a Curie temperature 320 K, atomic magnetic moment 0.307µB/Cr, and the easy-magnetization axis in film plane. Comparing bulk Cr4Te5 single-crystal, the critical exponent β=0.491 indicates that the magnetic interactions of thin film obey mean-field model rather than 3D Heisenberg model. This work will open a avenue for growing large-scale 2D ferromagnet and developing room temperature 2D magnet-based nanodevices.

Effects of Process Tube Position on Properties of Graphene Layers

2012 ◽  
Vol 1451 ◽  
pp. 57-62 ◽  
Author(s):  
Zafer Mutlu ◽  
Miroslav Penchev ◽  
Isaac Ruiz ◽  
Hamed Hosseini Bay ◽  
Shirui Guo ◽  
...  
Keyword(s):  
Large Scale ◽  
Growth Parameters ◽  
Industrial Applications ◽  
Quartz Tube ◽  
Large Area ◽  
High Quality ◽  
Practical Applications ◽  
Graphene Layers ◽  
Vis Spectroscopy ◽  
Tube Position

ABSTRACTGraphene, with unique electrical, optical and mechanical properties is a promising material in industrial applications, such as batteries, supercapacitors, transistors and semiconductor devices. These potential applications of graphene have motivated the development of large-scale synthesis of graphene on copper substrates by chemical vapor deposition (CVD). To enable practical applications of large-area, high quality graphene layers at the centimeter and wafer scales, process control needs to be implemented for optimizing the morphology and electrical properties and enable repeatable growth-cycle of graphene layers for process-line implementation. Here we investigate the effects of process quartz-tube position on the structural properties of graphene. Furthermore, we describe a procedure for process optimization of the growth parameters. Graphene is grown on copper foils by CVD, and transferred to the SiO2/Si and glass substrates. The detailed characterization of the graphene layers are conducted using Raman spectroscopy, optical microscopy (OM), scanning electron microscopy (SEM) and UV-vis spectroscopy. The experimental results show that the position of copper foil into the quartz tube plays a significant role in the Raman features of the graphene, and influences the optical, morphology and surface properties of graphene layers. We believe that these results will be useful for determining the optimum processing conditions of high quality graphene layers at the centimeter and wafer scales.

scholarly journals Utilizing complex oxide substrates to control carrier concentration in large-area monolayer MoS2 films

2021 ◽  
Vol 118 (9) ◽  
pp. 093103
Author(s):  
Xudong Zheng ◽  
Eli Gerber ◽  
Jisung Park ◽  
Don Werder ◽  
Orrin Kigner ◽  
...  
Keyword(s):  
Carrier Concentration ◽  
Complex Oxide ◽  
Monolayer Mos2 ◽  
Large Area ◽  
Oxide Substrates

scholarly journals All organic multiferroic magnetoelectric complexes with strong interfacial spin-dipole interaction

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Yuying Yang ◽  
Zhiyan Chen ◽  
Xiangqian Lu ◽  
Xiaotao Hao ◽  
Wei Qin
Keyword(s):  
Magnetic Field ◽  
Light Intensity ◽  
Room Temperature ◽  
Incident Light ◽  
Dipole Interaction ◽  
Interfacial Interaction ◽  
Magnetoelectric Coupling ◽  
Incident Light Intensity ◽  
Organic Ferromagnets ◽  
Magnetoelectric Coefficient

AbstractThe organic magnetoelectric complexes are beneficial for the development on flexible magnetoelectric devices in the future. In this work, we fabricated all organic multiferroic ferromagnetic/ferroelectric complexes to study magnetoelectric coupling at room temperature. Under the stimulus of external magnetic field, the localization of charge inside organic ferromagnets will be enhanced to affect spin–dipole interaction at organic multiferroic interfaces, where overall ferroelectric polarization is tuned to present an organic magnetoelectric coupling. Moreover, the magnetoelectric coupling of the organic ferromagnetic/ferroelectric complex is tightly dependent on incident light intensity. Decreasing light intensity, the dominated interfacial interaction will switch from spin–dipole to dipole–dipole interaction, which leads to the magnetoelectric coefficient changing from positive to negative in organic multiferroic magnetoelectric complexes.

In-situ construction of direct Z-scheme AgBr/α-Ag2WO4 heterojunction with promoted spatial charge migration and photocatalytic performance

2021 ◽  
Author(s):  
Xiao-Ya Zhai ◽  
Yifan Zhao ◽  
Guo-Ying Zhang ◽  
Bing-Yu Wang ◽  
Qi-Yun Mao
Keyword(s):  
Anion Exchange ◽  
Large Scale ◽  
Room Temperature ◽  
Photocatalytic Performance ◽  
Charge Migration ◽  
Time Saving ◽  
Spatial Charge ◽  
Construction Strategy ◽  
Large Scale Synthesis

In the work, a direct Z-scheme AgBr/α-Ag2WO4 heterojunction was prepared by in-situ anion exchange at room temperature. The construction strategy is energy- and time-saving for large scale synthesis. The α-Ag2WO4...

scholarly journals Rapid Single Image-Based DTM Estimation from ExoMars TGO CaSSIS Images Using Generative Adversarial U-Nets

2021 ◽  
Vol 13 (15) ◽  
pp. 2877
Author(s):  
Yu Tao ◽  
Siting Xiong ◽  
Susan J. Conway ◽  
Jan-Peter Muller ◽  
Anthony Guimpier ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Imaging System ◽  
Landing Site ◽  
Parameter Tuning ◽  
Processing Parameters ◽  
Input Image ◽  
Large Area ◽  
Laser Altimeter ◽  
Imaging Science

The lack of adequate stereo coverage and where available, lengthy processing time, various artefacts, and unsatisfactory quality and complexity of automating the selection of the best set of processing parameters, have long been big barriers for large-area planetary 3D mapping. In this paper, we propose a deep learning-based solution, called MADNet (Multi-scale generative Adversarial u-net with Dense convolutional and up-projection blocks), that avoids or resolves all of the above issues. We demonstrate the wide applicability of this technique with the ExoMars Trace Gas Orbiter Colour and Stereo Surface Imaging System (CaSSIS) 4.6 m/pixel images on Mars. Only a single input image and a coarse global 3D reference are required, without knowing any camera models or imaging parameters, to produce high-quality and high-resolution full-strip Digital Terrain Models (DTMs) in a few seconds. In this paper, we discuss technical details of the MADNet system and provide detailed comparisons and assessments of the results. The resultant MADNet 8 m/pixel CaSSIS DTMs are qualitatively very similar to the 1 m/pixel HiRISE DTMs. The resultant MADNet CaSSIS DTMs display excellent agreement with nested Mars Reconnaissance Orbiter Context Camera (CTX), Mars Express’s High-Resolution Stereo Camera (HRSC), and Mars Orbiter Laser Altimeter (MOLA) DTMs at large-scale, and meanwhile, show fairly good correlation with the High-Resolution Imaging Science Experiment (HiRISE) DTMs for fine-scale details. In addition, we show how MADNet outperforms traditional photogrammetric methods, both on speed and quality, for other datasets like HRSC, CTX, and HiRISE, without any parameter tuning or re-training of the model. We demonstrate the results for Oxia Planum (the landing site of the European Space Agency’s Rosalind Franklin ExoMars rover 2023) and a couple of sites of high scientific interest.

scholarly journals Time-resolved PIV measurements of a deflected submerged jet interacting with liquid-gas and liquid-liquid interfaces

2021 ◽  
Author(s):  
Stefan Puttinger ◽  
Mahdi Saeedipour
Keyword(s):  
Liquid Layer ◽  
Large Scale ◽  
Free Surface Flow ◽  
Industrial Applications ◽  
Liquid Pool ◽  
Surface Flow ◽  
Two Phase ◽  
Time Resolved ◽  
Submerged Jet ◽  
Major Interest

AbstractThis paper presents an experimental investigation on the interactions of a deflected submerged jet into a liquid pool with its above interface in the absence and presence of an additional lighter liquid. Whereas the former is a free surface flow, the latter mimics a situation of two stratified liquids where the liquid-liquid interface is disturbed by large-scale motions in the liquid pool. Such configurations are encountered in various industrial applications and, in most cases, it is of major interest to avoid the entrainment of droplets from the lighter liquid into the main flow. Therefore, it is important to understand the fluid dynamics in such configurations and to analyze the differences between the cases with and without the additional liquid layer. To study this problem, we applied time-resolved particle image velocimetry experiments with high spatial resolution. A detailed data analysis of a small layer beneath the interface shows that although the presence of an additional liquid layer stabilizes the oscillations of the submerged jet significantly, the amount of kinetic energy, enstrophy, and velocity fluctuations concentrated in the proximity of the interface is higher when the oil layer is present. In addition, we analyze the energy distribution across the eigenmodes of a proper orthogonal distribution and the distribution of strain and vortex dominated regions. As the main objective of this study, these high-resolution time-resolved experimental data provide a validation platform for the development of new models in the context of the volume of fluid-based large eddy simulation of turbulent two-phase flows.

scholarly journals Efficient and large-area all vacuum-deposited perovskite light-emitting diodes via spatial confinement

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peipei Du ◽  
Jinghui Li ◽  
Liang Wang ◽  
Liang Sun ◽  
Xi Wang ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Scale Production ◽  
Nonradiative Recombination ◽  
Large Area ◽  
Spatial Confinement ◽  
Light Emitting ◽  
Large Scale Production

AbstractWith rapid advances of perovskite light-emitting diodes (PeLEDs), the large-scale fabrication of patterned PeLEDs towards display panels is of increasing importance. However, most state-of-the-art PeLEDs are fabricated by solution-processed techniques, which are difficult to simultaneously achieve high-resolution pixels and large-scale production. To this end, we construct efficient CsPbBr3 PeLEDs employing a vacuum deposition technique, which has been demonstrated as the most successful route for commercial organic LED displays. By carefully controlling the strength of the spatial confinement in CsPbBr3 film, its radiative recombination is greatly enhanced while the nonradiative recombination is suppressed. As a result, the external quantum efficiency (EQE) of thermally evaporated PeLED reaches 8.0%, a record for vacuum processed PeLEDs. Benefitting from the excellent uniformity and scalability of the thermal evaporation, we demonstrate PeLED with a functional area up to 40.2 cm2 and a peak EQE of 7.1%, representing one of the most efficient large-area PeLEDs. We further achieve high-resolution patterned perovskite film with 100 μm pixels using fine metal masks, laying the foundation for potential display applications. We believe the strategy of confinement strength regulation in thermally evaporated perovskites provides an effective way to process high-efficiency and large-area PeLEDs towards commercial display panels.

Pattern Writing by Implantation in a Large-Scale PSII System With Planar Inductively Coupled Plasma Source

2000 ◽  
Vol 624 ◽  
Author(s):  
Lingling Wu ◽  
Hongjun Gao ◽  
Dennis M. Manos
Keyword(s):  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Lateral Diffusion ◽  
Plasma Source ◽  
Direct Writing ◽  
Large Area ◽  
Depth Profiles ◽  
Geometric Patterns ◽  
Planar Coil ◽  
Rf Antenna

ABSTRACTA large-scale plasma source immersion ion implantation (PSII) system with planar coil RFI plasma source has been used to study an inkless, deposition-free, mask-based surface conversion patterning as an alternative to direct writing techniques on large-area substrates by implantation. The apparatus has a 0.61 m ID and 0.51 m tall chamber, with a base pressure in the 10−8 Torr range, making it one of the largest PSII presently available. The system uses a 0.43 m ID planar rf antenna to produce dense plasma capable of large-area, uniform materials treatment. Metallic and semiconductor samples have been implanted through masks to produce small geometric patterns of interest for device manufacturing. Si gratings were also implanted to study application to smaller features. Samples are characterized by AES, TEM and variable-angle spectroscopic ellipsometry. Composition depth profiles obtained by AES and VASE are compared. Measured lateral and depth profiles are compared to the mask features to assess lateral diffusion, pattern transfer fidelity, and wall-effects. The paper also presents the results of MAGIC calculations of the flux and angle of ion trajectories through the boundary layer predicting the magnitude of flux as a function of 3-D location on objects in the expanding sheath

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