Article
Chemistry, Multidisciplinary
Mengkang Xu, Xinpeng Tian, Qian Deng, Qun Li, Shengping Shen
Summary: By introducing nanocracks and applying continuously varying mechanical loading, the evolution of flexoelectricity around the crack tips in SrTiO3, Ba0.67Sr0.33TiO3, and TiO2 samples has been successfully measured. This method provides a reliable way to identify the significance of the flexoelectric effect and may open a new avenue for the study of flexoelectricity involving multiple physics phenomena such as flexoelectronics and the flexo-photovoltaic effect.
Article
Materials Science, Multidisciplinary
Hui Ji, Shubao Shao, Kaiyuan Liu, Tonghui Wu, Shengping Shen, Shuwen Zhang, Minglong Xu
Summary: This study presents a mechanical design approach to enhance flexoelectricity by creating an elastic modulus gradient, and combining material design with non-uniform geometric shape, resulting in a significant improvement of the flexoelectric effect.
MECHANICS OF MATERIALS
(2022)
Article
Engineering, Mechanical
Yilun Xu
Summary: A non-local method for establishing GND based on a non-local domain integral has been developed and validated, showing improved accuracy in predicting material fatigue life. The comprehensive study on non-local domain effect revealed the necessity of applying the non-local GND method, as it resembles experimental observations and enhances stress field predictions compared to local methods.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Materials Science, Ceramics
Zhonghua Dai, Shuxuan Guo, Yun Gong, Zhiguo Wang
Summary: The study investigates the effect of doping graphite into SrTiO3 ceramic on the flexoelectric coefficient, finding that the doped material shows a significant increase in flexoelectric coefficient compared to pure STO, and introduces a new method for probing semiconductor flexoelectricity.
CERAMICS INTERNATIONAL
(2021)
Article
Chemistry, Physical
Di Guo, Pengwen Guo, Yuan Yao, Lele Ren, Mengmeng Jia, Wei Wang, Yulong Wang, Yufei Zhang, Aifang Yu, Junyi Zhai
Summary: This study demonstrates the significant enhancement of flexoelectric potential and flexotronics in single crystal silicon strips through bending, with the rate of change in Schottky barrier height increasing as the material becomes thinner. The flexoelectric polarization direction can be tuned by changing the bending direction. The working mechanism of flexoelectricity induced by the synergistic contribution of the surface piezoelectric effect and bulk flexoelectric effect is elucidated theoretically.
Article
Nanoscience & Nanotechnology
Qianwei Huang, Jiyuan Yang, Zibin Chen, Yujie Chen, Matthew J. Cabral, Haosu Luo, Fei Li, Shujun Zhang, Yulan Li, Zonghan Xie, Houbing Huang, Yiu-Wing Mai, Simon P. Ringer, Shi Liu, Xiaozhou Liao
Summary: This study demonstrates the feasibility of generating CDWs through mechanical stress and investigates the formation mechanism through experiments and simulations.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Zhen Liu, Xinrong Wen, Yang Wang, Yanmin Jia, Feifei Wang, Guoliang Yuan, Yaojin Wang
Summary: By extending flexoelectricity to electrochemical functionality, it is demonstrated that flexo-catalysis effect can be achieved in centrosymmetric nanoparticles to degrade organic dyes.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Physics, Applied
Minghao Zhao, Jianan Niu, Chunsheng Lu, Bingbing Wang, Cuiying Fan
Summary: The governing equation of a piezoelectric semiconductor (PSC) considering flexoelectricity and the strain gradient effect is derived in this paper. Theoretical analysis is carried out for a cantilever PSC nanowire subjected to a time-harmonic transverse shear force, revealing that the strain gradient effect has a greater impact on the natural frequency and stiffness of the nanowire compared to flexoelectricity. Conversely, flexoelectricity has a stronger influence on electric potential and carrier concentration. These findings provide insights for the design and optimization of PSC devices such as nanoscale energy harvesters.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Varun Harbola, Samuel Crossley, Seung Sae Hong, Di Lu, Yorick A. Birkholzer, Yasuyuki Hikita, Harold Y. Hwang
Summary: Young's modulus plays a crucial role in determining the mechanical behavior of materials, particularly in flexoelectric materials where the modulus may vary nonmonotonically with thickness and be influenced by strain gradients. Nanomechanical measurements of SrTiO3 crystalline membrane drumheads reveal unexpected thickness dependence of Young's modulus, with significantly different values obtained for predominantly bending and stretching deformations in membranes thinner than 20 nm. In this regime, a strain gradient elastic coupling of around 2.2 µN is extracted, suggesting potential applications in new operational regimes of nanoelectro-mechanics.
Article
Physics, Applied
Shuwen Zhang, Kaiyuan Liu, Hui Ji, Tonghui Wu, Minglong Xu, Shengping Shen
Summary: A new study predicted and experimentally verified the flexoelectricity in non-oriented liquids, opening up new possibilities for research in this field and highlighting the electromechanical properties of liquid materials.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Engineering, Multidisciplinary
Sanjeev Kumar
Summary: The local scaling symmetry of the Lagrange density is used to study the electro-mechanical coupling effects in elastic dielectrics. This approach not only explains the induced polarization and electric potential, but also considers the geometric foundations. By introducing minimal replacement and the concept of gauge compensating one form field, the gauge invariance of the Lagrange density is restored. Different components of the gauge invariant energy density are constructed using scale invariant gauge curvature. Numerical simulations and validation demonstrate the effectiveness of the theory. Explorations of this kind of coupling could have significant implications in various industrial and laboratory applications.
APPLIED MATHEMATICAL MODELLING
(2024)
Article
Engineering, Multidisciplinary
Anqing Li, Binglei Wang, Shengyou Yang
Summary: This paper reexamines the origin and characteristics of flexoelectricity, proposes a method to decompose the strain gradient into four parts, and reformulates the general isotropic flexoelectric theory based on these decomposed strain gradients.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Edmund Han, Shahriar Muhammad Nahid, Tawfiqur Rakib, Gillian Nolan, Paolo F. Ferrari, M. Abir Hossain, Andre Schleife, SungWoo Nam, Elif Ertekin, Arend M. van der Zande, Pinshane Y. Huang
Summary: The low bending stiffness of atomic membranes from van der Waals ferroelectrics such as alpha-In2Se3 allows strong coupling between electrical polarization and mechanical deformation at high strain gradients and nanoscale curvatures. By investigating the atomic structure and polarization at bends in multilayer alpha-In2Se3, researchers found that bent alpha-In2Se3 produces arcs and kinks, with the former preserving the original polarization and the latter containing ferroelectric domain walls that reverse the out-of-plane polarization. The study demonstrates the control over ferroelectric polarization and a strategy for nanoscale ferroelectric domain patterning.
Article
Mechanics
Kaiyuan Liu, Hui Ji, Tonghui Wu, Shengping Shen, Shuwen Zhang, Minglong Xu
Summary: This study proposes mechanical designs for two uniform strain-gradient schemes to investigate the effects of strain gradients. By eliminating the potential impact of non-uniform strain gradients, it promotes research on the flexoelectricity phenomenon.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Chemistry, Physical
Pao-Wen Shao, Meng-Chin Lin, Qian Zhuang, Jiawei Huang, Shi Liu, Hsiao-Wen Chen, Hsiang-Lin Liu, Yu-Jung Lu, Yung-Jung Hsu, Jyh-Ming Wu, Yi-Chun Chen, Ying-Hao Chu
Summary: This study reveals the existence of localized flexoelectric effect in ferroelastic twin texture of ferroelastic materials, and provides evidence that the flexoelectric effect confined at domain wall area facilitates photocarrier transport, which is further supported by dye-degradation and generation of reactive radicals.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Chemistry, Multidisciplinary
Sujiao Cao, Zhenyang Zhao, Yijuan Zheng, Zihe Wu, Tian Ma, Bihui Zhu, Chengdong Yang, Xi Xiang, Lang Ma, Xianglong Han, Yi Wang, Quanyi Guo, Li Qiu, Chong Cheng
Summary: Metal-N-coordinated centers supported by carbonaceous substrates have been synthesized and compared in terms of catalytic activities, substrate selectivities, kinetics, and reactive oxygen species (ROS) products. The electronic structures of the metal centers were found to be highly related to the ROS-catalytic paths and activities.
ADVANCED MATERIALS
(2022)
Article
Multidisciplinary Sciences
Chao Yang, Yi Wang, Daniel Putzky, Wilfried Sigle, Hongguang Wang, Roberto A. Ortiz, Gennady Logvenov, Eva Benckiser, Bernhard Keimer, Peter A. van Aken
Summary: This study investigates the microstructural characteristics and electronic structure of a NdNiO3 film grown by layer-by-layer molecular beam epitaxy. The researchers observe different configurations of Ruddlesden-Popper (RP) faults through aberration-corrected scanning transmission electron microscopy and spectroscopy. They also demonstrate the relationship between the valence change of nickel and strain and structure variation.
Article
Materials Science, Multidisciplinary
Jie Ji, Jia Yao, Yongchang Xu, Houzhao Wan, Bao Zhang, Lin Lv, Jingying Li, Nengze Wang, Zhaohan Zheng, Jun Zhang, Guokun Ma, Li Tao, Hanbin Wang, Yi Wang, Hao Wang
Summary: In this study, the introduction of Ni2+ into γ-MnO2 is proposed to promote proton migration kinetics, resulting in improved energy storage performance for aqueous Zn-MnO2 batteries.
ENERGY & ENVIRONMENTAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Tian Ma, Hao Cao, Shuang Li, Sujiao Cao, Zhenyang Zhao, Zihe Wu, Rui Yan, Chengdong Yang, Yi Wang, Peter A. van Aken, Li Qiu, Yang-Gang Wang, Chong Cheng
Summary: This study reports the design of a novel catalyst by confining atomic Pt in metal carbide lattices, achieving similar electronic structures and hydrogen evolution behaviors as metallic Pt. The catalyst exhibits higher mass activity in alkaline conditions compared to traditional Pt catalysts, providing a new pathway for constructing atomic-scale catalysts.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Heyong Wang, Zhan Chen, Fuyu Tian, Guanhaojie Zheng, Hongguang Wang, Tiankai Zhang, Jiajun Qin, Xingyu Gao, Peter A. van Aken, Lijun Zhang, Xiao-Ke Liu, Feng Gao
Summary: A strong correlation between lattice strain in perovskite films and the stability of PeLEDs is revealed in this study. The lifetime of high-efficiency PeLEDs is optimized by tailoring the lattice strain. The study also indicates that the degradation of the local perovskite lattice structure could be a degradation mechanism for long-term stable PeLEDs.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Varun Harbola, Yu-Jung Wu, Hongguang Wang, Sander Smink, Sarah C. Parks, Peter A. van Aken, Jochen Mannhart
Summary: A novel route is presented for fabricating nanocrystalline oxide structures via the self-assembly process of ultrathin membranes composed of the desired oxide. The self-assembly of nanocrystalline structures is driven by the dewetting of oxide membranes once they are transferred onto sapphire surfaces. The resulting nanostructures have highly anisotropic shapes determined by the crystal lattice of the transferred membrane, and exhibit exceptional quality with a pristine crystal structure and uniform stoichiometry.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Pengfei Cheng, Joachim Doell, Henry Romanus, Hongguang Wang, Peter A. van Aken, Dong Wang, Peter Schaaf
Summary: This article introduces a new noble-metal-free Al/AlN plasmonic nanostructure fabricated by reactive magnetron sputtering at an elevated temperature of 200 degrees C. The 3D Al/AlN nanostructures demonstrate highly efficient and broadband absorption as well as a strong photothermal conversion effect, indicating their potential in light-induced thermal imaging and photo-thermoelectric power generation. This novel fabrication method and the developed Al/AlN nanostructure offer a promising alternative to noble-metal plasmonic nanostructures for photonic applications.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Honglei Wang, Yunfei Jiao, Bing Wu, Dong Wang, Yueqi Hu, Fei Liang, Chen Shen, Andrea Knauer, Dan Ren, Hongguang Wang, Peter A. van Aken, Hongbin Zhang, Zdenek Sofer, Michael Graetzel, Peter Schaaf
Summary: We successfully exfoliated layered and nonlayered ultra-thin metal phosphorous trichalcogenides (MPCh(3)) nanosheets via wet grinding exfoliation (WGE), and studied the CO2 ECR mechanism of MPCh(3) as catalysts. Nonlayered SnPS3 nanosheets with exposed Sn atoms on the surface exhibited significantly improved catalytic activity, achieving formic acid selectivity of up to 31.6% with -7.51 mA cm(-2) at -0.65 V vs. RHE. This enhanced performance can be attributed to the formation of HCOO* via the first proton-electron pair addition on the SnPS3 surface, providing insights into the novel CO2 ECR mechanism of Sn-based and MPCh(3)-based catalysts.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Materials Science, Textiles
Maohua Zhang, Zhongzhi Guan, Yuhang Ren, Hongguang Wang
Summary: This paper presents a method for predicting multiscale damage of pultruded fiber-reinforced plastic (FRP) composites. The elastic properties of unidirectional yarns and fabrics were predicted using the representative volume units (RVEs) method. The microscopic predictions were then used as material parameters for the macroscopic laminate. 3D Hashin VUMAT subroutine and cohesive cells were employed to reflect intra-plate and inter-layer failures, respectively. The proposed numerical model was verified by experimental tests and further investigated the mechanical response of the pultruded FRP laminate.
FIBERS AND POLYMERS
(2023)
Article
Chemistry, Multidisciplinary
Chao Yang, Roberto A. Ortiz, Yi Wang, Wilfried Sigle, Hongguang Wang, Eva Benckiser, Bernhard Keimer, Peter A. van Aken
Summary: The polarity of the interface plays a crucial role in the physical properties of oxide heterointerfaces, as it can lead to specific modifications of the electronic and atomic structure. The recently discovered superconducting nickelate films in the NdNiO2/SrTiO3 interface may have important reconstruction effects, as bulk superconductivity has not been observed. Through four-dimensional scanning transmission electron microscopy and electron energy-loss spectroscopy, the effects of oxygen distribution, polyhedral distortion, elemental intermixing, and dimensionality in NdNiO2/SrTiO3 superlattices on SrTiO3 (001) substrates were studied. The results provide insights into the understanding of reconstructions at NdNiO2/SrTiO3 polar interfaces.
Article
Multidisciplinary Sciences
Dong Li, Hongguang Wang, Kaifeng Li, Bonan Zhu, Kai Jiang, Dirk Backes, Larissa S. I. Veiga, Jueli Shi, Pinku Roy, Ming Xiao, Aiping Chen, Quanxi Jia, Tien-Lin Lee, Sarnjeet S. Dhesi, David O. Scanlon, Judith L. MacManus-Driscoll, Peter A. van Aken, Kelvin H. L. Zhang, Weiwei Li
Summary: Transition metal oxides are considered promising candidates for the next generation of spintronic devices due to their controllable properties by strain, defects, and microstructure. In this study, the authors reveal the formation of ordered oxygen vacancies and suppression of CoO6 octahedral rotations in LaCoO3 films, explaining the origin of their ferromagnetic-insulating state. The findings provide valuable insights into the mechanisms of this state and suggest potential applications in low-power spintronic devices.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Xiaofei Zhao, Wen Ding, Hongguang Wang, Yize Wang, Yanjiang Liu, Yongdong Li, Chunliang Liu
Summary: This study investigated the effect of terahertz electromagnetic fields on the Kv1.2 potassium ion channel using molecular dynamics simulations. The results showed that an electromagnetic field with a 15 THz frequency significantly enhanced the permeability of the Kv1.2 channel, by 1.7 times compared to without an applied electric field. By analyzing the behavior of water molecules, it was found that the 15 THz frequency field shortened the duration of frozen and relaxation processes, increased the proportion of the direct knock-on mode, and thus enhanced the channel permeability of Kv1.2 potassium ion channel.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Honglei Wang, Yifan Bo, Malte Klingenhof, Jiali Peng, Dong Wang, Bing Wu, Joerg Pezoldt, Pengfei Cheng, Andrea Knauer, Weibo Hua, Hongguang Wang, Peter A. van Aken, Zdenek Sofer, Peter Strasser, Dirk M. Guldi, Peter Schaaf
Summary: A mixed solvent exfoliation surface deposition (MSESD) strategy is developed for the preparation of NiPS3 nanosheets and NiPS3/polyvinyl alcohol (PVA) converter. The NiPS3/PVA nanosheets improve the stability and form a 3D photothermal converter with a high evaporation rate and photothermal conversion efficiency.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Honglei Wang, Jun Shi, Jingyu Zhang, Zhehao Tao, Hongguang Wang, Qingqing Yang, Peter A. van Aken, Runfeng Chen
Summary: This study presents a facile and green method for preparing few-layer MoS2 nanosheets and nanocomposites, and demonstrates their potential in high-performance memory devices. The findings reveal the charge trapping and detrapping behaviors of the 2D MoS2-based nanocomposites.
Article
Materials Science, Multidisciplinary
Dong Li, Bonan Zhu, Dirk Backes, Larissa S. I. Veiga, Tien-Lin Lee, Hongguang Wang, Qian He, Pinku Roy, Jiaye Zhang, Jueli Shi, Aiping Chen, Peter A. van Aken, Quanxi Jia, Sarnjeet S. Dhesi, David O. Scanlon, Kelvin H. L. Zhang, Weiwei Li
Summary: Research shows that strain engineering can effectively control the electronic structure, magnetic and transport properties of La0.9Ba0.1MnO3 thin films. By adjusting the strain, the orbital occupancy of Mn can be changed, leading to significant modulation of the magnetic and electronic properties.
