Article
Materials Science, Multidisciplinary
Eiichi Kondoh
Summary: The effects of plasma treatment on the texture and grain size distribution of aluminum thin films on polyimide substrates have been investigated. Oxygen-argon plasma treatment increased the average grain size and enhanced the (111) film texture. Short oxygen-argon plasma treatment resulted in Al films with bimodal grain structure and even in-plane texture of {111}<11<(2)over bar>> type. The preferential nucleation and grain growth of (111) grains are discussed in terms of interface energy anisotropy.
Article
Chemistry, Physical
Neha Verma, Rob Delhez, Niek M. van der Pers, R. W. A. Hendrikx, R. M. Huizenga, Amarante J. Bottger
Summary: In this study, the microstructural changes of Pd thin films during hydrogen cycling were systematically investigated. The morphology, grain orientation, stress, and dislocation densities were analyzed for different substrate types. The results showed that the stress increase caused by lattice expansion and contraction during the Pd to Pd-hydride transition could be stabilized through grain boundary motion. Furthermore, crack-based stress relief mechanism was observed for Pd thin films on certain substrates. The findings highlight the importance of substrate compliance in enhancing the stability and mechanical properties of Pd thin films.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Materials Science, Multidisciplinary
Chaogang Ding, Wanji Chen, Shima Sabbaghianrad, Jie Xu, Debin Shan, Bin Guo, Terence G. Langdon
Summary: Ultrafine-grained pure titanium was obtained by high-pressure torsion, and its recrystallization behavior was investigated using in-situ transmission electron microscopy. The study showed that grain growth in the ultrafine-grained pure titanium thin film is significantly suppressed, with the combined effects of driving force and drag force on grain boundary migration being the primary cause of grain growth inhibition.
MATERIALS CHARACTERIZATION
(2021)
Article
Physics, Applied
Long Cheng, Heng Zhang, Ran Xu, Kevin Co, Nicolas Guiblin, Mojca Otonicar, Charles Paillard, Yujia Wang, Brahim Dkhil
Summary: The interaction between domain structure and defects in ferroelectric thin films has been a focus of research. This study demonstrates the role of dislocations in stabilizing the domains of PbTiO3 films on a SrTiO3 substrate during post-annealing above 550 degrees C. The effects of single dislocations and dislocation pairs on domain formation were also explored.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Sandra Stangebye, Yin Zhang, Saurabh Gupta, Ting Zhu, Olivier Pierron, Josh Kacher
Summary: Transmission electron microscopy (TEM) imaging relies on high energy electrons for atomic scale resolution. The electron beam (e-beam) was found to enhance plastic deformation in nanocrystalline Al, leading to an increase in plastic strain rate and a decrease in activation volume, while having a weaker effect on ultrafine-grained Au. The e-beam effect is due to an effective temperature increase from additional atomic fluctuations.
Article
Polymer Science
Bryce J. Kingsley, Paul R. Chiarot
Summary: Electrospray deposition is a rapid method for creating films, utilizing charged microdroplets to deposit solute material on a target surface. In-situ UV exposure reduces processing time for creating thin films.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Hongxing Li, Seiichiro Ii, Nobuhiro Tsuji, Takahito Ohmura
Summary: The study observed the formation of grain boundaries through non-homogeneous plastic deformation in body centered cubic iron, indicating the critical role of non-homogeneous stress/strain field in grain boundary formation. The activation of various slip systems due to stress inhomogeneity led to the gathering of wall-like tangled dislocations around the boundary, evolving into sharp grain boundaries with increasing plastic strain.Adjacent grains with simple smooth shapes in the same specimen did not form sharp grain boundaries.
SCRIPTA MATERIALIA
(2022)
Article
Chemistry, Physical
Alexander Vogel, Martin F. Sarott, Marco Campanini, Morgan Trassin, Marta D. Rossell
Summary: Increased data storage densities are needed for the next generation of nonvolatile random access memories and data storage devices based on ferroelectric materials, but these devices may face a loss of their ferroelectric properties with intensified miniaturization. Therefore, understanding the impact of nanoscale defects on ferroelectric switching dynamics is crucial.
Article
Chemistry, Physical
Wenzheng Jiang, Lei Zhu, Lingli Chen, Yumeng Yang, Xi Yu, Xiaolong Li, Zhiqiang Mu, Wenjie Yu
Summary: In this study, an in situ method based on synchrotron X-ray diffraction (XRD) system was proposed to characterize the longitudinal piezoelectric constant d(33) of Al1-xScxN film. The measurement results showed the piezoelectric effect of Al1-xScxN films by lattice spacing variation upon applied external voltage. The in situ synchrotron XRD measurement was proven to be an effective method for precise piezoelectric coefficient d(33) characterization.
Article
Materials Science, Coatings & Films
Edyta Kobierska, Stanislav Zak, Sabrina Hirn, Megan J. Cordill, Robert Franz, Marisa Rebelo de Figueiredo
Summary: In this study, the tribological properties of Mo films deposited on polyimide substrates were assessed using the ball-on-disc test. The wear mechanisms and induced stresses were analyzed by microscopy and simulation, providing insights into the tribological response of metallic films on compliant substrates.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Sachiko Ono, Hidetaka Asoh
Summary: The process of hot water sealing of anodic alumina films was investigated, revealing that as sealing time increases, the quantity and size of boehmite flakes within the films also increase, ultimately forming a three-layered structure.
Article
Multidisciplinary Sciences
Wenzheng Wei, Dung Vu, Zhan Zhang, Frederick J. J. Walker, Charles H. H. Ahn
Summary: We report on the superconductivity in Nd1-xEuxNiO2, where Eu is used as a 4f dopant. By employing an in situ molecular beam epitaxy reduction process, we achieve the superconducting phase, providing an alternative method to induce superconductivity in infinite-layer nickelates compared to the ex situ CaH2 reduction process. The Nd1-xEuxNiO2 samples exhibit a step-terrace surface structure, have a T-c onset of 21 K at x = 0.25, and show a large upper critical field possibly due to Eu 4f doping.
Article
Physics, Applied
M. E. Twigg, G. G. Jernigan
Summary: Research indicates that in heteroepitaxial semiconductor films, thinner and mechanically stiffer blocking layers are more effective in reducing the Peach-Koehler force, thereby preventing dislocation generation.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Polymer Science
Marco Cen-Puc, Andreas Schander, Minerva G. Vargas Gleason, Walter Lang
Summary: Different surface treatment methods were applied to polyimide films, and the adhesive effects were compared. The research found that using oxygen plasma treatment with reactive ion etching equipment is the most promising approach for promoting adhesion between polyimide films.
Article
Chemistry, Multidisciplinary
So Yoon Lee, Tae-Hwan Huh, Hye Rim Jeong, Young-Je Kwark
Summary: Silver/polyimide (Ag/PI) composite films with enhanced heat dissipation properties were prepared in this study. Ag particles were formed in various locations by reducing AgNO3, and two types of soluble polyimides, Matrimid and HPI, were utilized. The interaction between HPI and Ag ions led to uniform size distribution of Ag particles, affecting heat emission characteristics and improving heat dissipation properties of the composite films.
Article
Materials Science, Multidisciplinary
Alexander Jelinek, Stanislav Zak, Markus Alfreider, Daniel Kiener
Summary: Direct laser writing by two-photon lithography enables the manufacturing of tailored 3D objects with high precision. Mechanical properties of materials can be accessed through micromechanical testing. This study presents an approach to overcome the issue of undefined geometries by introducing a slight taper within the geometry at initially printed layers.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Saba Ahmad, Tobias Brink, Christian H. Liebscher, Gerhard Dehm
Summary: In the past few decades, it has been discovered that a single grain boundary can exist in different stable and metastable states with different atomic structures. However, experimental insights into the atomic structure are rarely reported. This study reports two different microstates of incoherent Sigma 3 [111] (11 (2) over bar) grain boundaries in an aluminum thin film grown on sapphire, which have slightly different structural units. Molecular statics simulations are used to understand the differences between these states and strain is found to potentially contribute to the stability of one state over the other.
Article
Materials Science, Multidisciplinary
Hanna Tsybenko, J. Manoj Prabhakar, Michael Rohwerder, Gerhard Dehm, Steffen Brinckmann
Summary: The development of wear-resistant steels requires understanding of deformation behavior and chemical evolution in cementite (Fe3C) under tribological loading. This study examines the elemental and phase distributions in bulk polycrystalline cementite with minor fractions of graphite, iron, and wustite after single-pass sliding wear. The results show that severe plastic deformation leads to partial decomposition and mechanical mixing of non-cementite inclusions and partial elemental homogenization in the outermost deformed region.
Article
Materials Science, Multidisciplinary
Benjamin Seligmann, Markus Alfreider, Michael Wurmshuber, Daniel Kiener
Summary: Microelectronic devices require material systems combining multiple layers of material for proper operation. This study investigates the internal stress states and their influence on deformation behavior in a Si-WTi-Cu material system using in situ thermomechanical cantilever bending experiments. The experiments reveal that the Cu layer undergoes partial plastic deformation during heating, which may result in failure of devices. A model incorporating plastic deformation and known residual stresses is proposed and verified by Finite Element Analysis to assess the internal stress and strain states based on in situ observation.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Engineering, Biomedical
Michael Wurmshuber, Jana Wilmers, Jongil Kim, Sang Ho Oh, Swantje Bargmann, Daniel Kiener
Summary: The limpet tooth is considered as the strongest material in nature, with a reported strength value of up to 6.5 GPa. The recent discovery of microscale auxeticity in the tooth's leading part provides a possible explanation for this extreme strength. Through micromechanical experiments, it is found that the hardness values obtained from nanoindentation are lower than the strength observed in micropillar compression tests. This unique behavior is attributed to local tensile strains during indentation, resulting from the microscale auxeticity, leading to microdamage in the auxetic regions of the tooth microstructure.
ACTA BIOMATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
Michael Wurmshuber, Markus Alfreider, Stefan Wurster, Michael Burtscher, Reinhard Pippan, Daniel Kiener
Summary: The brittleness of tungsten is a challenge for its application as a divertor material in nuclear fusion reactors. Grain refinement is a promising strategy to increase its fracture toughness, but it also promotes intercrystalline crack growth. This study explores the use of grain boundary doping with boron and hafnium to enhance the fracture toughness of ultrafine-grained tungsten. The results show that doping with boron and hafnium can improve the fracture toughness of ultrafine-grained tungsten, with values up to 27 MPa root m.
Article
Materials Science, Multidisciplinary
Wenjun Lu, Wenqi Guo, Zhangwei Wang, Jianjun Li, Fengchao An, Gerhard Dehm, Dierk Raabe, Christian H. Liebscher, Zhiming Li
Summary: In this study, a novel strategy is developed to mitigate the embrittlement of sigma phase particles in high-entropy alloys (HEAs) by utilizing displacive transformation and heterogeneous structures. The deformation behavior study reveals that the displacive transformation from face-centered cubic (FCC) to hexagonal close packed (HCP) phase effectively suppresses the propagation of microcracks in brittle sigma particles and contributes to high work hardening behavior. The transformation induced stress-relaxation around the regions containing brittle sigma particles in heterogeneously structured HEAs results in ultimate tensile strengths as high as -1.2 GPa while maintaining a ductility up to -50%.
Article
Materials Science, Multidisciplinary
T. Kluensner, M. Krobath, R. Konetschnik, C. Tritremmel, V. Maier-Kiener, D. Samardzic, W. Ecker, C. Czettl, C. Mitterer, D. Kiener
Summary: In this study, micromechanical specimens were produced using focused ion beam milling to investigate the fracture behavior of rough substrate-coating interfaces with complex defect structure. It was found that a stable value of the maximum principal stress triggering fracture in the ceramic-ceramic interfaces was observed for inclination angles >= 45 degrees. The interface strength was determined by observing the crack path at the substrate-coating interface via scanning electron microscopy and analyzing the effectively loaded interface area values.
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Hanna Bishara, Lena Langenohl, Xuyang Zhou, Baptiste Gault, James P. Best, Gerhard Dehm
Summary: The study focuses on the effect of Fe-alloying on the resistivities of grains and grain boundaries in Cu thin films. Cu films with varying grain sizes and Fe compositions were prepared. The properties, morphology, and compositions of bulk and grain boundaries were analyzed using different methods. Both local electrical measurements and global resistivity characterization were performed to obtain specific resistivities and calculate the grain boundary reflection coefficient. It was found that alloying significantly increased the resistivity of grain boundaries while causing only minor influence on the grain interior.
SCRIPTA MATERIALIA
(2023)
Correction
Multidisciplinary Sciences
Lena Langenohl, Tobias Brink, Rodrigo Freitas, Timofey Frolov, Gerhard Dehm, Christian H. Liebscher
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Xuyang Zhou, Ali Ahmadian, Baptiste Gault, Colin Ophus, Christian H. Liebscher, Gerhard Dehm, Dierk Raabe
Summary: Grain boundaries, the defects between differently oriented crystals, play an important role in solute segregation and material properties. The interplay of structure and composition of grain boundaries at the atomic level remains unclear. Through charge-density imaging and atom probe tomography, the authors reveal that the atomic motifs control the chemical properties of grain boundaries and enable the targeted design and passivation for various applications.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Gloria Graf, Malina Seyffertitz, Petra Spoerk-Erdely, Helmut Clemens, Andreas Stark, Lukas Hatzenbichler, David Holec, Michael Burtscher, Daniel Kiener, Xiaobing Li, Kui Liu
Summary: In order to promote the use of intermetallic γ-TiAl based alloys in the aircraft and automotive sector, recent research has focused on the development of low-cost titanium aluminides. The addition of manganese has shown potential to replace more expensive alloying elements and improve the ductility. However, Mn-containing alloys are prone to the formation of undesired brittle phases, which can affect the ductility. This study investigated the transformation kinetics and stability range of a specific brittle phase in a low-cost Ti-42Al-5Mn alloy using experimental and computational approaches. The results provide valuable insights for the future design of low-cost γ-TiAl based alloys.
Article
Materials Science, Multidisciplinary
Sung-Gyu Kang, Ramil Gainov, Daniel Heussen, Soeren Bieler, Zhongji Sun, Kerstin Weinberg, Gerhard Dehm, Rajaprakash Ramachandramoorthy
Summary: This study demonstrates the fabrication of copper lattice structures using green laser in laser-powder bed fusion, which have well-defined unit cells and dense microstructure. The deformation behavior of these structures under different strain rates is investigated and rationalized, suggesting their suitability for dynamic loading applications.
MATERIALS & DESIGN
(2023)
Article
Materials Science, Multidisciplinary
Alexander Jelinek, Stanislav Zak, Megan J. Cordill, Daniel Kiener, Markus Alfreider
Summary: Two-photon lithography enables the design and characterization of novel micromechanical specimens, expanding the possibilities for miniaturized technologies. This study presents a methodology for automated specimen fabrication and testing, and analyzes the influence of parameters on the essential work of fracture. The findings provide a foundation for statistical fracture evaluation in other resin materials and thin film systems.
MATERIALS & DESIGN
(2023)
Article
Nanoscience & Nanotechnology
Michael Burtscher, Markus Alfreider, Christina Kainz, Daniel Kiener
Summary: The technical potential of WCu alloys is limited by the modest fracture characteristics of the material system in its coarse-grained condition. To address this, a W-50 at.% Cu composite with a nanocrystalline microstructure was processed using high-pressure torsion deformation. The resulting microstructures were quantified, and the mechanical properties were investigated. The study found that the processed specimens had smaller grain sizes and increased amount of mechanically intermixed W in the Cu grains. The mechanical properties of the processed specimens were comparable to those of the coarse-grained specimens.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
Jie Zhang, Xiaoyang Chen, MingJian Ding, Jiaqiang Chen, Ping Yu
Summary: This study enhances the compositional inhomogeneity of relaxor ferroelectric thin films to improve their dielectric temperature stability. The prepared films exhibit a relatively high dielectric constant and a very low variation ratio of dielectric constant over a wide temperature range.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Xiaoyu Chen, Ranran Zhang, Hao Zou, Ling Li, Qiancheng Zhu, Wenming Zhang
Summary: Polyaniline-manganese dioxide composites exhibit high conductivity, long discharge platform, and stable circulation, and the specific capacity is increased by providing additional H+ ions to participate in the reaction.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Xutao Huang, Yinping Chen, Jianjun Wang, Gang Lu, Wenxin Wang, Zan Yao, Sixin Zhao, Yujie Liu, Qian Li
Summary: This study aims to establish a novel approach to better understand and predict the behavior of materials with multi-scale lamellar microstructures. High-resolution reconstruction and collaborative characterization methods are used to accurately represent the microstructure. The mechanical properties of pearlite are investigated using crystal plasticity simulation and in-situ scanning electron microscopy tensile testing. The results validate the reliability of the novel strategy.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Cheng Chen, Fanchao Meng, Jun Song
Summary: This study systematically investigated the unfaulting mechanism of single-layer interstitial dislocation loops in irradiated L12-Ni3Al. The unfaulting routes of the loops were uncovered and the symmetry breaking during the unfaulting processes was further elucidated. A continuum model was formulated to analyze the energetics of the loops and predict the unfaulting threshold.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Darshan Bamney, Laurent Capolungo
Summary: This work investigates the formation of adjoining twin pairs (ATPs) at grain boundaries (GBs) in hexagonal close-packed (hcp) metals, focusing on the co-nucleation (CN) of pairs of deformation twins. A continuum defect mechanics model is proposed to study the energetic feasibility of CN of ATPs resulting from GB dislocation dissociation. The model reveals that CN is preferred over the nucleation of a single twin variant for low misorientation angle GBs. Further analysis considering GB character and twin system alignment suggests that CN events could be responsible for ATP formation even at low m' values.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Bing Han, Zhengqian Fu, Guoxiang Zhao, Xuefeng Chen, Genshui Wang, Fangfang Xu
Summary: This study investigates the behavior of electric-field induced antiferroelectric to ferroelectric (AFE-FE) phase transition and reveals the evolution of atomic displacement ordering as the cause for the transition behavior changing from sharp to diffuse. The novel semi-ordered configuration results from the competing interaction between long-range displacement modulation and compositional inhomogeneity, which leads to a diffuse AFE-FE transition while maintaining the switching field.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Akib Jabed, Golden Kumar
Summary: This study demonstrates that cryogenic rejuvenation promotes homogeneous-like flow and increases ductility in metallic glass samples. Conversely, annealing has the opposite effect, resulting in a smoother fracture surface.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Xin Ji, Yan Chong, Satoshi Emura, Koichi Tsuchiya
Summary: A heterogeneous microstructure in Ti-15Mo-3Al alloy with heterogeneous distributions of Mo element and omega(iso) precipitates has achieved a four-fold increase in tensile ductility without a loss of tensile strength, by blocking the propagation of dislocation channels and preventing the formation of micro-cracks.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Amit Samanta, Prasanna Balaprakash, Sylvie Aubry, Brian K. Lin
Summary: This study proposes a combined large-scale first principles approach with machine learning and materials informatics to quickly explore the chemistry-composition space of advanced high strength steels (AHSS). The distribution of aluminum and manganese atoms in iron is systematically explored using first principles calculations to investigate low stacking fault energy configurations. The use of an automated machine learning tool, DeepHyper, speeds up the computational process. The study provides insights into the distribution of aluminum and manganese atoms in systems containing stacking faults and their effects on the equilibrium distribution.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Guowei Zhou, Yuanzhe Hu, Zizheng Cao, Myoung Gyu Lee, Dayong Li
Summary: In this work, a physics-constrained neural network is used to predict grain-level responses in FCC material by incorporating crystal plasticity theory. The key feature, shear strain rate of slip system, is identified based on crystal plasticity and incorporated into the loss function as physical constitutive equations. The introduction of physics constraints accelerates the convergence of the neural network model and improves prediction accuracy, especially for small-scale datasets. Transfer learning is performed to capture complex in-plane deformation of crystals with any initial orientations, including cyclic loading and arbitrary non-monotonic loading.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Pengfei Yang, Qichang Li, Zhongying Wang, Yuxiao Gao, Wei Jin, Weiping Xiao, Lei Wang, Fusheng Liu, Zexing Wu
Summary: In this study, the HER performance of Ru-based catalysts is significantly improved through the dual-doping strategy. The obtained catalyst exhibits excellent performance in alkaline freshwater and alkaline seawater, and can be stably operated in a self-assembled overall water splitting electrolyzer.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Ilias Bikmukhametov, Garritt J. Tucker, Gregory B. Thompson
Summary: Depositing a Ni-1at. % P film can facilitate the formation of multiple quintuple twin junctions, resulting in a five-fold twin structure and a pentagonal pyramid surface topology. The ability to control material structures offers opportunities for creating novel surface topologies, which can be used as arrays of field emitters or textured surfaces.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Zening Yang, Weiwei Sun, Zhengyu Sun, Mutian Zhang, Jin Yu, Yubin Wen
Summary: Multicomponent oxides (MCOs) have wide applications and accurately predicting their thermal expansion remains challenging. This study introduces an innovative attention-based deep learning model, which achieves improved performance by using two self-attention modules and demonstrates adaptability and interpretability.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Ze Liu, Cai Chen, Yuanxun Zhou, Lanting Zhang, Hong Wang
Summary: This study attempts to address the gap in cooling rates between thin film deposition and bulk metallic glass (BMG) casting by correlating the glass-forming range (GFR) determined from combinatorial materials chips (CMCs) with the glass-forming ability (GFA) of BMG. The results show that the full-width at half maximum (FWHM) of the first sharp diffraction peak (FSDP) is a good indicator of BMG GFA, and strong positive correlations between FWHM and the critical casting diameter (Dmax) are observed in various BMG systems. Furthermore, the Pearson correlation coefficients suggest possible similarities in the GFA natures of certain BMG pairs.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Mike Schneider, Jean-Philippe Couzinie, Amin Shalabi, Farhad Ibrahimkhel, Alberto Ferrari, Fritz Koermann, Guillaume Laplanche
Summary: This work aims to predict the microstructure of recrystallized medium and high-entropy alloys, particularly the density and thickness of annealing twins. Through experiments and simulations, a database is provided for twin boundary engineering in alloy development. The results also support existing theories and empirical relationships.
SCRIPTA MATERIALIA
(2024)
