The Experts below are selected from a list of 20691 Experts worldwide ranked by ideXlab platform
Hailin Peng - One of the best experts on this subject based on the ideXlab platform.
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controlled synthesis of topological insulator Nanoplate arrays on mica
Journal of the American Chemical Society, 2012Co-Authors: Hui Li, Wenhui Dang, Wenshan Zheng, Yulin Chen, Di Wu, Kai Wang, Hailin PengAbstract:The orientation- and position-controlled synthesis of single-crystal topological insulator (Bi2Se3 and Bi2Te3) Nanoplate arrays on mica substrates was achieved using van der Waals epitaxy. Individual ultrathin Nanoplates with the lateral dimension up to ∼0.1 mm or uniform thickness down to 1–2 nm were produced. Single-Dirac-cone surface states of Nanoplate aggregates were confirmed by angle-resolved photoemission spectroscopy measurements. The large-grain-size, single-crystal Nanoplate arrays grown on mica can act as facile platforms for a combination of spectroscopy and in situ transport measurements, which may open up new avenues for studying exotic physical phenomena, surface chemical reactions, and modification in topological insulators.
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Epitaxial heterostructures of ultrathin topological insulator Nanoplate and graphene
Nano Letters, 2010Co-Authors: Wenhui Dang, Pu Wang, Hailin Peng, Hui Li, Zhong Fan LiuAbstract:The authors present a van der Waals epitaxy of high-quality ultrathin Nanoplates of topological insulator Bi2Se3 on a pristine graphene substrate using a simple vapor-phase deposition method. Sub-10-nm-thick Nanoplates of layered Bi2Se3 with defined orientations can be epitaxially grown on a few-layer pristine graphene substrate. We show the evolution of Raman spectra with the number of Bi2Se3 layers on few-layer graphene. Bi2Se3 Nanoplates with a thickness of three quintuple-layers (3-QL) exhibit the strongest Raman intensity. Strain effects in the Bi2Se3/graphene Nanoplate heterostructures is also studied by Raman spectroscopy. 1-QL and 2-QL Bi2Se3 Nanoplates experience tensile stress, consistent with compressive stress in single-layer and bilayer graphene substrates. Our results suggest an approach for the synthesis of epitaxial heterostructures that consist of an ultrathin topological insulator and graphene, which may be a new direction for electronic and spintronic applications.
Farzad Ebrahimi - One of the best experts on this subject based on the ideXlab platform.
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Nonlinear dynamics and vibration of reinforced piezoelectric scale-dependent plates as a class of nonlinear Mathieu–Hill systems: parametric excitation analysis
Engineering with Computers, 2020Co-Authors: Ali Shariati, S. Hamed S. Hosseini, Farzad Ebrahimi, Ali ToghroliAbstract:This work is motivated by little research in the nonlinear dynamic instability of the reinforced piezoelectric Nanoplates. This paper, using an analytical approach, presents bifurcations in the nonlinear dynamic instability of the reinforced piezoelectric Nanoplates caused by the parametric excitation. An axial parametric load is applied to excite the system, while the reinforced piezoelectric Nanoplate is under an applied electric voltage, simultaneously. The governing equations of motion for the reinforced piezoelectric Nanoplate embedded on a visco-Pasternak foundation are derived using the nonlocal elasticity theory, Hamilton’s principle, and nonlinear von Karman theory. A class of nonlinear the Mathieu–Hill equation is established to determine the bifurcations and the regions of the nonlinear dynamic instability. The numerical results are performed, while the emphasis is placed on investigating the effect of the applied electric voltage, visco-Pasternak foundation coefficients, and the parametric excitation. It is found that the damping coefficient is responsible of the bifurcation point variation, while the amplitude response depends on the term of the natural frequency.
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Dynamic modeling of embedded Nanoplate systems incorporating flexoelectricity and surface effects
Microsystem Technologies, 2019Co-Authors: Farzad Ebrahimi, Mohammad Reza BaratiAbstract:In this research, vibration characteristics of a flexoelectric Nanoplate in contact with Winkler-Pasternak foundation are investigated based on nonlocal elasticity theory considering surface effects. This non-classical Nanoplate model contains flexoelectric effect to capture coupling of strain gradients and electrical polarizations. Moreover, the nonlocal elasticity theory is employed to study the nonlocal and long-range interactions between the particles. The present model can degenerate into the classical model if the nonlocal parameter, flexoelectric and surface effects are omitted. Hamilton’s principle is employed to derive the governing equations and the related boundary conditions which are solved applying a Galerkin-based solution. Natural frequencies are verified with those of previous papers on flexoelectric Nanoplates. It is illustrated that flexoelectricity, nonlocality, surface stresses, elastic foundation and boundary conditions affects considerably the vibration frequencies of piezoelectric Nanoplates.
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Static stability analysis of embedded flexoelectric Nanoplates considering surface effects
Applied Physics A, 2017Co-Authors: Farzad Ebrahimi, Mohammad Reza BaratiAbstract:In this paper, electromechanical buckling behavior of size-dependent flexoelectric Nanoplates is investigated based on nonlocal and surface elasticity theories. Flexoelectricity represents the coupling between strain gradients and electrical polarizations. Flexoelectric Nanoplates can tolerate higher buckling loads compared with conventional piezoelectric Nanoplates, especially at lower thicknesses. The flexoelectric Nanoplate is in contact with a two-parameter elastic foundation, which consists of infinite linear springs and a shear layer. Nonlocal elasticity theory of Eringen is applied in the analysis of flexoelectric Nanoplates for the first time. The residual surface stresses which are usually neglected in the modeling of flexoelectric Nanoplates are incorporated into nonlocal elasticity to provide better understanding of the physics of the problem. Applying an analytical solution which satisfies various boundary conditions, the governing equations obtained from Hamilton’s principle are solved. The reliability of the present approach is verified by comparing the obtained results with those provided in literature. Finally, the influences of nonlocal parameter, surface effect, plate geometrical parameters, elastic foundation and boundary conditions on the buckling characteristics of flexoelectric Nanoplates are explored.
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Wave propagation in embedded inhomogeneous nanoscale plates incorporating thermal effects
Waves in Random and Complex Media, 2017Co-Authors: Farzad Ebrahimi, Mohammad Reza Barati, Ali DabbaghAbstract:AbstractIn this article, an analytical approach is developed to study the effects of thermal loading on the wave propagation characteristics of an embedded functionally graded (FG) Nanoplate based on refined four-variable plate theory. The heat conduction equation is solved to derive the nonlinear temperature distribution across the thickness. Temperature-dependent material properties of Nanoplate are graded using Mori–Tanaka model. The nonlocal elasticity theory of Eringen is introduced to consider small-scale effects. The governing equations are derived by the means of Hamilton’s principle. Obtained frequencies are validated with those of previously published works. Effects of different parameters such as temperature distribution, foundation parameters, nonlocal parameter, and gradient index on the wave propagation response of size-dependent FG Nanoplates have been investigated.
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Damping vibration analysis of smart piezoelectric polymeric Nanoplates on viscoelastic substrate based on nonlocal strain gradient theory
Smart Materials and Structures, 2017Co-Authors: Farzad Ebrahimi, Mohammad Reza BaratiAbstract:This paper develops a nonlocal strain gradient plate model for damping vibration analysis of smart piezoelectric polymeric Nanoplates resting on visco-Pasternak medium. For more accurate analysis of piezoelectric Nanoplate, the proposed theory contains two scale parameters related to the nonlocal and strain gradient effects. Viscoelastic effect is considered based on Kelvin–Voit model. Governing equations of a nonlocal strain gradient smart Nanoplate on viscoelastic substrate are derived via Hamilton's principle. Galerkin's method is implemented to solve the governing equations. Effects of different factors such as viscoelasticity, nonlocal parameter, length scale parameter, applied voltage and Winkler–Pasternak parameters on damping vibration characteristics of a Nanoplate are studied.
Haibo Zeng - One of the best experts on this subject based on the ideXlab platform.
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epitaxial zno nanowire on Nanoplate structures as efficient and transferable field emitters
Advanced Materials, 2013Co-Authors: Jizhong Song, Sergei A Kulinich, Jian Yan, Caixia Kan, Haibo ZengAbstract:Highly epitaxial ZnO nanowire-on-Nanoplate structures as efficient and transferable electron field emitters are reported here. Well-faceted ZnO Nanoplates can be used as efficient substrates for the epitaxial growth of nanowires with a sharp and high-quality interface, which significantly improves its field emitter performance. Because of its scalable preparation, high performance and facile transfer, the novel material is of high potential for applications in various optoelectronic devices.
Wenhui Dang - One of the best experts on this subject based on the ideXlab platform.
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controlled synthesis of topological insulator Nanoplate arrays on mica
Journal of the American Chemical Society, 2012Co-Authors: Hui Li, Wenhui Dang, Wenshan Zheng, Yulin Chen, Di Wu, Kai Wang, Hailin PengAbstract:The orientation- and position-controlled synthesis of single-crystal topological insulator (Bi2Se3 and Bi2Te3) Nanoplate arrays on mica substrates was achieved using van der Waals epitaxy. Individual ultrathin Nanoplates with the lateral dimension up to ∼0.1 mm or uniform thickness down to 1–2 nm were produced. Single-Dirac-cone surface states of Nanoplate aggregates were confirmed by angle-resolved photoemission spectroscopy measurements. The large-grain-size, single-crystal Nanoplate arrays grown on mica can act as facile platforms for a combination of spectroscopy and in situ transport measurements, which may open up new avenues for studying exotic physical phenomena, surface chemical reactions, and modification in topological insulators.
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Epitaxial heterostructures of ultrathin topological insulator Nanoplate and graphene
Nano Letters, 2010Co-Authors: Wenhui Dang, Pu Wang, Hailin Peng, Hui Li, Zhong Fan LiuAbstract:The authors present a van der Waals epitaxy of high-quality ultrathin Nanoplates of topological insulator Bi2Se3 on a pristine graphene substrate using a simple vapor-phase deposition method. Sub-10-nm-thick Nanoplates of layered Bi2Se3 with defined orientations can be epitaxially grown on a few-layer pristine graphene substrate. We show the evolution of Raman spectra with the number of Bi2Se3 layers on few-layer graphene. Bi2Se3 Nanoplates with a thickness of three quintuple-layers (3-QL) exhibit the strongest Raman intensity. Strain effects in the Bi2Se3/graphene Nanoplate heterostructures is also studied by Raman spectroscopy. 1-QL and 2-QL Bi2Se3 Nanoplates experience tensile stress, consistent with compressive stress in single-layer and bilayer graphene substrates. Our results suggest an approach for the synthesis of epitaxial heterostructures that consist of an ultrathin topological insulator and graphene, which may be a new direction for electronic and spintronic applications.
Hui Li - One of the best experts on this subject based on the ideXlab platform.
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controlled synthesis of topological insulator Nanoplate arrays on mica
Journal of the American Chemical Society, 2012Co-Authors: Hui Li, Wenhui Dang, Wenshan Zheng, Yulin Chen, Di Wu, Kai Wang, Hailin PengAbstract:The orientation- and position-controlled synthesis of single-crystal topological insulator (Bi2Se3 and Bi2Te3) Nanoplate arrays on mica substrates was achieved using van der Waals epitaxy. Individual ultrathin Nanoplates with the lateral dimension up to ∼0.1 mm or uniform thickness down to 1–2 nm were produced. Single-Dirac-cone surface states of Nanoplate aggregates were confirmed by angle-resolved photoemission spectroscopy measurements. The large-grain-size, single-crystal Nanoplate arrays grown on mica can act as facile platforms for a combination of spectroscopy and in situ transport measurements, which may open up new avenues for studying exotic physical phenomena, surface chemical reactions, and modification in topological insulators.
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Epitaxial heterostructures of ultrathin topological insulator Nanoplate and graphene
Nano Letters, 2010Co-Authors: Wenhui Dang, Pu Wang, Hailin Peng, Hui Li, Zhong Fan LiuAbstract:The authors present a van der Waals epitaxy of high-quality ultrathin Nanoplates of topological insulator Bi2Se3 on a pristine graphene substrate using a simple vapor-phase deposition method. Sub-10-nm-thick Nanoplates of layered Bi2Se3 with defined orientations can be epitaxially grown on a few-layer pristine graphene substrate. We show the evolution of Raman spectra with the number of Bi2Se3 layers on few-layer graphene. Bi2Se3 Nanoplates with a thickness of three quintuple-layers (3-QL) exhibit the strongest Raman intensity. Strain effects in the Bi2Se3/graphene Nanoplate heterostructures is also studied by Raman spectroscopy. 1-QL and 2-QL Bi2Se3 Nanoplates experience tensile stress, consistent with compressive stress in single-layer and bilayer graphene substrates. Our results suggest an approach for the synthesis of epitaxial heterostructures that consist of an ultrathin topological insulator and graphene, which may be a new direction for electronic and spintronic applications.
