Article
Physics, Multidisciplinary
Zheng Chen, Zhenyu Cheng, Liang Du, Yong Yang
Summary: In this study, the quantum size effects in multilayer graphene sheets were investigated using first principles methods within the framework of density functional theory. Four different types of functionals were adopted to describe the van der Waals interactions between graphene layer sheets. The results showed that the PBE functional could not well describe the van der Waals interactions, while the other three methods exhibited similar results indicating the stability of the layered graphene structure. The density of states at zero temperature indicated that multilayer graphene sheets were semi-metals independent of the number of layers. The finite temperature density of states demonstrated oscillating behavior between odd and even numbers of layers, revealing the presence of quantum size effects.
Article
Chemistry, Physical
Xiaojing Hao, Zi Wang, Jiaye Su
Summary: In recent experiments with multilayer graphene sheets, the arrangement of pore sizes was found to affect water transport, with a more concentrated arrangement facilitating higher water flux and flow efficiency. Using molecular dynamics simulations, two different pore size arrangements (uniform and concentrated) were studied, showing that the water dynamics bifurcate under different friction environments. The results provide insights for the design of high flux nanofluidic devices.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Materials Science, Multidisciplinary
Radu Stefan Stirbu, Liliana Mitoseriu
Summary: The hysteretic character of the electromechanic coupling in porous piezoeceramics was investigated using modeling and analysis to determine the relationships between polarization, strain, and porosity. The study calculated the local electrical and mechanical responses and determined effective dielectric and piezoelectric constants. The results showed a nonlinear decrease in polarization and deformation with porosity and discussed the effects of different polarization states on the effective permittivity and piezoelectric constants.
COMPUTATIONAL MATERIALS SCIENCE
(2024)
Article
Chemistry, Physical
Zhaolin Qiu, Zhibo Zhang, Yongnan Xiong, Xing Luo, Zhiqiang Li, Kaihong Zheng, Wangyu Hu
Summary: Molecular dynamics simulations were conducted to explore the impact of graphene sheet size on the strengthening mechanism of Al-graphene composites during nanoindentation. The results showed that the graphene sheets acted as dislocation blockers, leading to dislocation pile-up near the graphene-matrix interface and strengthening the Al matrix. Interestingly, the strengthening mechanism was highly dependent on the size of the graphene sheet. When the indenter was not in contact with the graphene sheets, the nanoindentation force increased as the graphene sheet size decreased, reaching a maximum value at a graphene sheet size of 30 angstroms. On the other hand, when the indenter contacted the graphene sheets, the force decreased with increasing graphene sheet size due to the superior strength of the graphene sheets.
APPLIED SURFACE SCIENCE
(2022)
Article
Engineering, Civil
Jui-Liang Lin, Wen-Hui Chen, Fu-Pei Hsiao, Yuan-Tao Weng, Wen-Cheng Shen, Pu-Wen Weng, Shu-Hsien Chao, Lap-Loi Chung, Shyh-Jiann Hwang
Summary: By combining altered hysteretic models into three distorted numerical models, and then comparing the results of the four numerical models using incremental dynamic analysis, the effect of hysteretic models on the seismic responses of the building across the full range has been elucidated.
ENGINEERING STRUCTURES
(2021)
Article
Chemistry, Physical
Chaochen Xu, Zhijiang Ye, Philip Egberts
Summary: The insertion of water into 2D nanofilms leads to increased friction and decreased lubrication, indicating performance degradation of 2D materials in ambient conditions.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Luis D. Zambrano Palma, Marcos G. Menezes, Rodrigo B. Capaz
Summary: In this study, the rippling instabilities of multilayer graphene and graphite were investigated using computational methods. The critical compressive strain and number of layers required to induce the rippling instability were determined, and the results were discussed in comparison with continuum and atomistic approaches.
Article
Materials Science, Ceramics
Sheng Tong
Summary: The paper introduces a model of dielectric breakdown strength for ferroelectric films, which integrates thermal breakdown and defect models. The relationship between electric field, dimensional parameters, and operating temperature was verified through experiments. The study also found that the recoverable electric energy density is directly proportional to the square of the breakdown electric field.
JOURNAL OF ADVANCED CERAMICS
(2021)
Article
Chemistry, Multidisciplinary
Somnath Kale, Adrian Petraru, Hermann Kohlstedt, Rohit Soni
Summary: Domain walls separating differently oriented polarization regions greatly impact nanoscale materials and device functionalities. The authors demonstrate the effect of ferroelectric film thickness on the scaling behavior of domain wall dynamics and roughness exponents, and reveal a transition from two-dimensional to quasi-one-dimensional dimensionality. These findings provide new insights into nanoscale ferroelectricity and have implications for future nanodevices.
Article
Engineering, Geological
C. W. W. Ng, D. Peprah-Manu, C. Zhou
Summary: It is recognized that stress can affect the pore characteristics of unsaturated soil. To understand this better, eight water retention tests were conducted to evaluate the effects of pore size distribution and pore shape on the hysteretic water retention behavior. The results showed that pore structure plays an important role in the water retention curve.
Article
Chemistry, Physical
Sihan Liu, Ke Duan, Li Li, Xuelin Wang, Yujin Hu
Summary: Researchers proposed a multilayer coarse-grained MD model to simulate the mechanical behaviors of graphene structures, significantly increasing the simulation scale and reducing computational time, providing an important tool for designing novel graphene-based materials.
Article
Chemistry, Physical
Vahid Mortazavi, Ali Moosavi, Ali Nouri-Borujerdi
Summary: This research evaluates water desalination by charged multilayer graphene using molecular dynamics simulations and investigates the influence of electric charge amount and geometric parameters. It finds that distributing the electric charge appropriately on the carbon atoms around the pores of graphene enhances water flow rate and salt rejection efficiency, while increasing the interlayer distance diminishes the effect of electric charge on water flux.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Materials Science, Ceramics
Zhuo Yu, Jiangtao Zeng, Liaoying Zheng, Anthony Rousseau, Guorong Li, Abdelhadi Kassiba
Summary: Lead-free BiFeO3-BaTiO3-Bi(Mg2/3Nb1/3)O-3 (BFBT-BMN) ceramics with different grain sizes were fabricated using high-energy ball milling technique. The reduction in grain size leads to an increase in recoverable energy storage density and the presence of polar nanoregions, enhancing the energy storage properties of the ceramics. Transmission electron microscopy revealed the dynamic and weakly correlated polar nanoregions structure in the fine-grained ceramics, contributing to the significant enhancement of energy storage density.
CERAMICS INTERNATIONAL
(2021)
Article
Physics, Condensed Matter
Yugesh Kumar, Sukadev Sahoo, Amit K. Chakraborty
Summary: This article utilized MD simulations to analyze the mechanical properties of graphene under various conditions, revealing that factors such as defect location, type, and temperature can influence its elastic moduli and constants. Additionally, the properties of multilayer graphene sheets and SiC-graphene composites showed improvement with an increase in the number of continuous graphene layers.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Materials Science, Multidisciplinary
Chengdong Liu, Xian Zi, Hui-Miao Li, Kai-Ge Gao, Jiawang Hong, Jun Tao, Zi-Shuo Yao
Summary: This study investigates the effects of H/D isotopic substitution on a weak H-bonded compound and reveals that anisotropic deuteration of the complex cations leads to significant changes in its ferroelectric properties.
Article
Nanoscience & Nanotechnology
Kyle P. Kelley, Sergei Kalinin, Eugene Eliseev, Shivaranjan Raghuraman, Stephen Jesse, Peter Maksymovych, Anna N. Morozovska
Summary: Ferroelectric domain walls are fascinating objects in condensed matter physics with a wide range of functional behaviors. However, most studies have focused on bias-induced dynamics and transport behaviors. This article introduces a scanning probe microscopy approach that combines piezoresponse force microscopy (PFM) with a dynamically heated probe, allowing for exploration of thermal polarization dynamics and phase transitions at individual domain walls. The strong and weak modulation regimes for thermal PFM are discussed, along with the potential applications of the heated probe approach for various functional SPM measurements.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yongtao Liu, Jonghee Yang, Benjamin J. Lawrie, Kyle P. Kelley, Maxim Ziatdinov, Sergei V. Kalinin, Mahshid Ahmadi
Summary: The increasing photovoltaic efficiency and stability of metal halide perovskites (MHPs) are attributed to the improvement in understanding the microstructure of polycrystalline MHP thin films. A workflow combining conductive atomic force microscopy (AFM) measurement with a machine learning (ML) algorithm was designed to systematically investigate the grain boundaries in MHPs. This approach revealed that the properties of grain boundaries play critical roles in MHP stability.
Article
Chemistry, Physical
Yongtao Liu, Jonghee Yang, Rama K. Vasudevan, Kyle P. Kelley, Maxim Ziatdinov, Sergei Kalinin, Mahshid Ahmadi
Summary: We demonstrate an active machine learning framework for driving an automated scanning probe microscope (SPM) to discover the microstructures responsible for specific aspects of transport behavior in metal halide perovskites (MHPs). This approach allows the microscope to discover the microstructural elements that maximize the onset of conduction, hysteresis, or any other characteristic derived from a set of current-voltage spectra. It provides new opportunities for exploring the origins of materials functionality in complex materials by SPM and can be integrated with other characterization techniques.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Review
Materials Science, Multidisciplinary
Jonghee Yang, Sergei V. Kalinin, Ekin D. Cubuk, Maxim Ziatdinov, Mahshid Ahmadi
Summary: Low-dimensional hybrid perovskites combine the physical functionalities of inorganic materials and complexity of organic molecules to form self-organized complex structures. These materials offer high-performance optoelectronics and versatile applications, and can be produced cost-effectively.
Letter
Chemistry, Physical
Andrew R. Akbashev, Sergei V. Kalinin
Article
Computer Science, Artificial Intelligence
Yongtao Liu, Anna N. Morozovska, Eugene A. Eliseev, Kyle P. Kelley, Rama Vasudevan, Maxim Ziatdinov, Sergei V. Kalinin
Summary: Using hypothesis-learning-driven automated scanning probe microscopy (SPM), this study investigates the bias-induced transformations in various devices and materials. It is crucial to understand these mechanisms on the nanometer scale with a wide range of control parameters, which is experimentally challenging. The hypothesis-driven SPM autonomously identifies the mechanisms of bias-induced domain switching and reveals the importance of kinetic control.
Article
Computer Science, Artificial Intelligence
Arpan Biswas, Rama Vasudevan, Maxim Ziatdinov, Sergei Kalinin
Summary: Unsupervised and semi-supervised ML methods like VAE are widely used in physics, chemistry, and materials sciences for disentangling representations and finding latent manifolds in complex experimental data. This study explores a latent Bayesian optimization approach for hyperparameter trajectory optimization in unsupervised and semi-supervised ML, demonstrated by joint-VAE with rotational invariances. The method is applied to finding joint discrete and continuous rotationally invariant representations in the MNIST database and a plasmonic nanoparticles material system.
MACHINE LEARNING-SCIENCE AND TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Yongtao Liu, Anna N. Morozovska, Ayana Ghosh, Kyle P. Kelley, Eugene A. Eliseev, Jinyuan Yao, Ying Liu, Sergei Kalinin
Summary: In this study, the local curvature and strain effects on polarization in CIPS were investigated using piezoresponse force microscopy and spectroscopy. The finite element Landau-Ginzburg-Devonshire model was introduced to explain the observed behaviors and decouple the curvature and strain effects in 2D CIPS. The results showed that bending induced ferrielectric domains in CIPS and the polarization-voltage hysteresis loops differed in bending and nonbending regions. These studies provide important insights into the fabrication of curvature-engineered nanoelectronic devices.
Article
Physics, Applied
Jinyuan Yao, Yongtao Liu, Shaoqing Ding, Yanglin Zhu, Zhiqiang Mao, Sergei V. Kalinin, Ying Liu
Summary: Ferroelectricity in van der Waals layered material has attracted significant attention. The ferroelectric properties of CuInP2S6 (CIPS), which is the only van der Waals layered material that has demonstrated ferroelectricity in the bulk, have been observed to persist even at a few nanometers thickness. However, the potential device applications of CIPS' ferroelectric properties are just beginning to be explored.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Kyle P. Kelley, Anna N. Morozovska, Eugene A. Eliseev, Yongtao Liu, Shelby S. Fields, Samantha T. Jaszewski, Takanori Mimura, Sebastian Calderon, Elizabeth C. Dickey, Jon F. Ihlefeld, Sergei V. Kalinin
Summary: Ferroelectricity in binary oxides such as hafnia and zirconia has attracted attention due to unconventional physical mechanisms and potential integration into semiconductor workflows. Recent research suggests that factors such as electrochemical boundary conditions and strain heavily influence the ferroelectric properties. The interplay between ferroelectric and structural instabilities, coupled with non-local screening, explains the emergence of these properties.
Article
Materials Science, Multidisciplinary
Anna N. Morozovska, Eugene A. Eliseev, Venkatraman Gopalan, Long-Qing Chen
Summary: We propose an analytical Landau-Ginzburg (LG) theory that describes the charge density waves coupled with lattice and electronic long-range order parameters. The theory is applicable to various long-range order phenomena, such as superconducting Cooper pairs, structural distortions, electric polarization, and magnetization. We introduce a biquadratic coupling between the charge density gradient and the long-range order parameters, which plays a critical role in the appearance of spatially modulated phases in charge-ordered ferroics and high-temperature superconductors.
Article
Materials Science, Multidisciplinary
Anna N. Morozovska, Eugene A. Eliseev, Ayana Ghosh, Mykola E. Yelisieiev, Yulian M. Vysochanskii, Sergei V. Kalinin
Summary: In this study, the strain-induced polarization reversal in a ferroelectric CuInP2S6 (CIPS) thin film with conductive electrodes is explored. The study reveals an unusually strong effect of mismatch strain on the out-of-plane polarization reversal, hysteresis loop shape, dielectric susceptibility, and piezoelectric response of CIPS films.
