Article
Materials Science, Multidisciplinary
Paulina Rudzinska, Jakub Wawrzyniak, Katarzyna Grochowska, Jakub Karczewski, Jacek Ryl, Katarzyna Siuzdak
Summary: To meet the increasing global demand for clean electricity, affordable and efficient photoactive semiconductors are constantly being developed. A one-step calcination method combined with hydrogenation has been investigated as an alternative to the time-consuming furnace annealing for crystallization and modification of high-surface titania nanotubes. The evaluation of the crystallinity of the electrode based on Raman and X-ray diffraction, followed by optical and electrochemical investigation, revealed significantly improved performance of the modified material, including over 2.6-fold higher photocurrent densities and enhanced visible light absorption.
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
T. F. Jing, H. B. Zheng, Q. Liao, L. X. Song, H. B. Peng, Y. H. Wen
Summary: Thermomechanical processing can facilitate the homogeneous introduction of more and thinner deformation nanotwins into bulk TWIP steel, resulting in enhanced yield strength.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Anushree Dutta, Dyutiman Barman, Jayanta Das
Summary: Hardening was observed in Ni-Zr-Al ultrafine lamellar eutectic composite via nano-precipitation, with significant enhancement of strength upon annealing and stable lamellar morphology up to high temperatures. Addition of Al facilitates the formation of small precipitates in the matrix, leading to improved material performance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Multidisciplinary
Pingdong Wei, Xuejie Yu, Yujia Fang, Lei Wang, Hao Zhang, Caizhen Zhu, Jie Cai
Summary: This article proposes a strategy to produce a hierarchically structured cellulose hydrogel through solution annealing and dual cross-linking treatment approaches. The cellulose hydrogels exhibit high water content and excellent mechanical properties, making them promising candidates for flexible electronics and biomedical devices.
Article
Materials Science, Multidisciplinary
Guangya Li, Yang Yang, Boyuan Gou, Jinyu Zhang, Jiao Li, Yaqiang Wang, Lingfei Cao, Gang Liu, Xiangdong Ding, Jun Sun
Summary: By controlling the defects of coherent twin boundaries (CTBs) through Cr segregation at kinks and grain boundaries (GBs), high strength and excellent structural-mechanical stability can be achieved, providing a new perspective for the design of purified Cu alloys.
Article
Materials Science, Multidisciplinary
Kunpeng Zhang, Ruifeng Dou, Pengfei Zhao, Xianhao Li, Liang Zhou, Xunliang Liu, Zhi Wen
Summary: Annealing is necessary to reduce residual stress and no-load loss in 3D coil cores. In the absence of real-time monitoring of temperature and stress, the trial and error method is commonly used to determine annealing process parameters. An annealing simulation experiment was conducted on grain-oriented electrical steel (GOES) to investigate the effect of soaking time on iron loss and magnetic flux density. The mechanical properties of GOES were tested and true stress-strain curves at different temperatures were obtained. Based on existing research and experimental results, an anisotropic thermal mechanical coupling model of the 3D coil core was established. An optimization scheme for the annealing process of the 3D coil core, considering temperature difference, stress, and strain, was obtained. The annealing process was simulated and optimized using the coupling model based on onsite measured parameters. Results show that the total annealing time was shortened by approximately 18.7% without increasing stress and strain.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Sara Valvez, Paulo N. B. Reis, Jose A. M. Ferreira
Summary: This study aims to analyse the annealing effect on the mechanical properties of PETG, carbon fibre reinforced PETG (PETG + CF) and Kevlar fibre reinforced PETG (PETG + KF). The final dimensions vary with temperature and exposure time regardless of the material, showing that the addition of fibres had no significant influence. The presence of fibres affects the radius of curvature, and this parameter is highly dependent on the type of fibre. Higher temperatures and exposure times generally lead to higher hardness values, achieving improvements of about 20% over untreated material. Bending properties increase with exposure time and temperature for composites, while in the case of neat PETG they increase with temperature and decrease with exposure time. After the annealing treatment, significant improvements were observed in bending strength, bending modulus, impact strength, stress relaxation, and creep behavior for all materials.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Chaogang Ding, Jie Xu, Debin Shan, Bin Guo, Terence G. Langdon
Summary: The microstructural evolution and mechanical properties of Cu/Nb NMMs under different annealing temperatures were investigated. The results showed that the nanolayered structure of the NMMs is maintained at temperatures below 800°C, but thermal instability occurs at 1000°C, leading to the disintegration of the nanolayered structure. Tensile tests revealed enhanced strain hardening and improved ultimate tensile strength and elongation in the 1000°C annealed samples.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Yong Liu, Jian Sun, Xinqing Han, Qing Huang, Eva Zarkadoula, Miguel L. Crespillo, Ning Gao, Xuelin Wang, Peng Liu
Summary: The evolution of microstructure and mechanical properties of low-energy heavy-ion-irradiated LiTaO3 crystals annealed at different temperatures was investigated. The study revealed the formation of voids before annealing and the emergence of a new directional diffusion path of defects after annealing. Furthermore, it was found that the annealing process led to the formation of different phases and also affected the hardness of the irradiated samples.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Ceramics
Ali Mercan, Rifki Terzioglu, Muhsin Ugur Dogan, Senol Kaya, Umit Erdem, Gurcan Yildirim, Cabir Terzioglu, Ahmet Varilci
Summary: This study investigated the effects of different annealing temperatures on the surface morphological and mechanical performance properties of Zr surface-layered Bi-2223 materials. It was observed that annealing at 650°C resulted in superior performance due to enhanced deformation and the presence of Zr ions acting as nucleation centers to prevent crack propagation. Diffusion mechanisms also contributed to improved performance by increasing the random distribution of granular structures and reducing coupling problems between grains.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Hyeon Jeong Lee, Brigita Darminto, Sudarshan Narayanan, Maria Diaz-Lopez, Albert W. Xiao, Yvonne Chart, Ji Hoon Lee, James A. Dawson, Mauro Pasta
Summary: In this study, we investigate the influence of grain, grain boundary, and interfacial resistance on the Li-ion conductivity in Li2OHCl1-xBrx antiperovskite solid electrolytes. By using various techniques such as thermal expansion coefficient, atomistic calculations, electrochemical impedance spectroscopy, and X-ray photoelectron spectroscopy, we reveal the effects of structural defects and composition on the conductivity, providing insights for improving Li-ion conductivity in lithium hydroxide halide antiperovskites.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Materials Science, Multidisciplinary
Fabio Negreiros Ribeiro, Dolores Ribeiro Ricci Lazar, Valter Ussui, Nelson Batista de Lima, Juliana Marchi, Gustavo Martini Dalpian
Summary: In this study, crystals of 3 mol-% Y2O3 (3YSZ) doped with various amounts of Ti were investigated at the density-functional level. It was found that adding a small amount of Ti to zirconia can make YSZ materials more energetically and kinetically stable.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Engineering, Multidisciplinary
LingKun Zhang, MingLiang Wang, Rui Huang, XiaoHu Chen, Zheng Ren, Tao He, YiPing Lu
Summary: Adopting the idea of thermal modification of conventional Si-containing eutectic alloys, this study aimed to improve the fracture plasticity of the brittle CoFeNi2(Ti3Si5)(0.16) high-entropy alloy by heating it under various annealing conditions. The result showed that the eutectic microstructure transformed from lamellar + network morphologies to granular + irregular morphologies after annealing. The resulting alloy exhibited excellent mechanical properties, including an ultimate compressive strength of 1980 +/- 50 MPa, fracture plasticity of similar to 16.6% +/- 1%, and hardness of similar to 448 +/- 15 HV.
SCIENCE CHINA-TECHNOLOGICAL SCIENCES
(2023)
Article
Polymer Science
Assia Zennaki, Latifa Zair, Khadidja Arabeche, Lina Benkraled, Ulrich Maschke, Abdelkader Berrayah
Summary: This study investigated the effects of annealing temperature and time on the crystalline phase transition in PLA using DSC and DMA. A small exothermal peak was observed at 130 degrees C, indicating the disorder-to-order phase transition, when the sample was annealed at 80 degrees C for 10-30 hours. The sample annealed at 90-110 degrees C showed a double melting behavior, suggesting the alpha'-alpha phase transition. DMA results showed a significant increase in the glass modulus at 80 degrees C for 3 hours, followed by an improvement at 120 degrees C for all samples. These findings suggest that the improvement in E-g is correlated with the increase in crystallinity and the alpha'-alpha phase transition.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Materials Science, Ceramics
Haoran Wei, Wenhao He, Qiangzhi Li, Yuanying Yu, Renxin Xu, Jing Zhou, Jie Shen, Wen Chen
Summary: This study developed a glass fiber/polytetrafluoroethylene (GF/PTFE) composite, which achieved a thermal-mechanical stable dielectric composite with low dielectric constant and low dielectric loss through a paper-making process, forming a skeleton structure with PTFE matrix in the fiber network.
CERAMICS INTERNATIONAL
(2023)
Article
Microscopy
Xiaohui Huang, Dzmitry Hlushkou, Di Wang, Ulrich Tallarek, Christian Kubel
Summary: This study systematically investigates the reconstruction reliability of three mainstream algorithms in mesoporous materials. The results show that DART outperforms the other two methods in reliably revealing small pores and narrow channels, especially when the number of projections is strongly constrained.
Article
Nanoscience & Nanotechnology
L. Morsdorf, A. Kashiwar, C. Kuebel, C. C. Tasan
Summary: Tempering is commonly used in high strength steel microstructures to rearrange carbon atoms, but its nano-scale interaction with crystallographic defects is challenging to observe experimentally. In this study, we investigate the redistribution of carbon atoms along martensite grain boundaries in low carbon steel after quenching and tempering using transmission electron microscopy (TEM) and atom probe tomography (APT). Our findings reveal that the amount of carbon segregation to martensite grain boundaries depends on the boundary type, and the growth behavior of cementite precipitates differs at low- and high-angle grain boundaries due to crystallographic constraints. We also demonstrate the impact of carbon redistribution on the mechanical properties by comparing hardness results from boundary-containing probe volumes to nanoindentation results from pure bulk martensite volumes.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Chemistry, Multidisciplinary
Sangjun Kang, Di Wang, Arnaud Caron, Christian Minnert, Karsten Durst, Christian Kuebel, Xiaoke Mu
Summary: Scanning/transmission electron microscopy (S/TEM) techniques have been used to analyze shear bands in metallic glasses for decades in order to improve their mechanical properties. However, conventional S/TEM lacks the ability to directly characterize the local strain and atomic structure of amorphous materials. In this study, 4-dimensional-STEM (4D-STEM) is applied to directly map and correlate the local strain and atomic structure at the nanometer scale in deformed metallic glasses. The results provide a new understanding of the formation of shear bands in metallic glasses.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Jasmin-Clara Burger, Sebastian Gutsch, Vanessa Wollersen, Di Wang, Bjorn Christian, Zhe Fu, Oliver Ambacher, Christian Kubel, Margit Zacharias
Summary: SnO2 nanowires were grown on r-plane sapphire substrates and characterized by scanning electron microscopy and atomic force microscopy, which revealed their highly oriented growth towards the substrate edges. High-resolution transmission electron microscopy and strain mapping were used to analyze the crystallographic alignment and defect distribution within the nanowire cross section. The findings were compared to freestanding SnO2 nanowires and SnO2 thin films on sapphire substrates.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Patrick Bottke, Katharina Hogrefe, Julia Kohl, Suliman Nakhal, Alexandra Wilkening, Paul Heitjans, Martin Lerch, H. Martin R. Wilkening
Summary: The visualization of atomic or ionic jump processes on a nanometer length scale is important for understanding diffusion pathways in solid electrolytes. This study used high-resolution 6Li nuclear magnetic resonance (NMR) spectroscopy to investigate Li+ exchange processes in Li3VF6. The results confirmed the preferred diffusion pathways and provided further insights into ion dynamics between corner-shared Li-bearing polyhedra.
MATERIALS RESEARCH BULLETIN
(2023)
Article
Nanoscience & Nanotechnology
Antje Dollmann, Julia S. Rau, Beatrix Bieber, Lakshmi Mantha, Christian Kuebel, Alexander Kauffmann, Aditya Srinivasan Tirunilai, Martin Heilmaier, Christian Greiner
Summary: The microstructural evolution under tribological load has a significant impact on the friction and wear response of the tribological system. However, the mechanistic understanding of these changes at an elementary level is still limited. In this study, the temporal sequence of deformation mechanisms under tribological load was investigated, focusing on the activation of twin systems in the CoCrNi material. The experimental analysis revealed the temporal sequence of the active twinning systems, providing insights into the stress field under tribological load.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Applied
J. Proff, M. Mail, A. Lindner, A. Scheuer, M. Bendrich, E. Quinet, A. Schuler, T. Scherer, C. Kuebel, M. Votsmeier
Summary: The diffusivity in the upper Cu-Chabazite layer of a dual layer ammonia oxidation catalyst with a lower Pt layer was investigated using FIB-SEM and CO oxidation measurements. FIB-SEM data showed an estimated effective diffusivity of 0.31, while CO oxidation experiments yielded a lower value of 0.11. NH3 oxidation experiments confirmed the effectiveness of the CO-derived diffusivity coefficient. The reason for the discrepancy between FIB-SEM and CO oxidation results requires further investigation.
TOPICS IN CATALYSIS
(2023)
Article
Multidisciplinary Sciences
Kai Wang, Weibo Hua, Xiaohui Huang, David Stenzel, Junbo Wang, Ziming Ding, Yanyan Cui, Qingsong Wang, Helmut Ehrenberg, Ben Breitung, Christian Kuebel, Xiaoke Mu
Summary: High entropy oxides (HEOs) with chemically disordered multi-cation structure have attracted significant attention as negative electrode materials for batteries. However, the mechanisms behind their outstanding electrochemical performance and the so-called 'cocktail effect' have not been fully understood. In this study, the authors investigate the behavior of each element in the HEO Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O during electrochemical reaction and connect it to the nanoscale structure, revealing the multi-cations synergy and explaining the 'cocktail effect'. The findings demonstrate the importance of elemental diversity in optimizing multi-cation electrode materials for batteries.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Antonio Gentile, Stefanie Arnold, Chiara Ferrara, Stefano Marchionna, Yushu Tang, Julia Maibach, Christian Kuebel, Volker Presser, Riccardo Ruffo
Summary: The use of composites with two-dimensional materials and conversion/alloying materials, such as SnO2, can improve the performance of lithium-ion batteries and overcome the mechanical instability issue. This study presents a 50/50 SnO2/Ti3C2Tz nanocomposite that demonstrates excellent cycling and rate performance. The synergistic behavior of the two components in the nanocomposite enables partial reversibility of the conversion reaction.
ADVANCED MATERIALS INTERFACES
(2023)
Review
Electrochemistry
Erwin Hueger, Lukas Riedel, Jing Zhu, Jochen Stahn, Paul Heitjans, Harald Schmidt
Summary: Li-Nb-O-based insertion layers are used in Li-ion batteries to protect electrodes and electrolytes and enhance Li transport. This study reviews the suitability of different Li-Nb-O-based compounds for battery operation, especially amorphous LiNbO3 films. Experimental results show that the amorphous LiNbO3 films have higher porosity and better Li diffusivity compared to other similar metal oxides. The films exhibit high reversible capacity and fast cycling, which make them suitable for improved battery performance.
Article
Nanoscience & Nanotechnology
Beatriz Mendoza-Sanchez, Enrique Samperio-Niembro, Oleksandr Dolotko, Thomas Bergfeldt, Christian Ku''bel, Michael Knapp, Christopher E. Shuck
Summary: This study comprehensively investigates the synthesis of MXene, with a specific focus on the properties of etched materials. Through different experimental conditions and various characterization techniques, it is found that the elemental composition, particle size, and crystal structure of the MAX precursor are critically relevant to the etching process and properties of etched materials. Additionally, XRD studies reveal the advantages of using a HF/HCl mix over only HF, in terms of crystal-structure-type of acid correlations.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Sondes Bauer, Berkin Nergis, Xiaowei Jin, Reinhard Schneider, Di Wang, Christian Kuebel, Vaclav Holy, Lukas Horak, Klaus Seemann, Sven Ulrich, Tilo Baumbach
Summary: This study investigates the effect of a platinum underlayer on the microstructure, crystalline quality, morphology, chemical composition, and magnetic properties of BaFe12O19 films grown on YSZ(111) substrate. It is found that a 25 nm thick platinum underlayer is unable to withstand dewetting during the growth of BaFe12O19 layer, while a 75 nm thick underlayer provides a smooth and continuous interface, improving the orientation, coercivity, and anisotropy fields of BaFe12O19 films. Comprehensive characterization techniques are used to analyze the structure and composition of the deposited films and their interfaces. This study aims to understand the mechanisms controlling the magnetic properties of BaFe12O19 films for tailored applications.
Article
Materials Science, Multidisciplinary
C. N. Shyam Kumar, Clemens Possel, Simone Dehm, Venkata Sai Kiran Chakravadhanula, Di Wang, Wolfgang Wenzel, Ralph Krupke, Christian Kuebel
Summary: Polymer pyrolysis is a versatile method to synthesize graphenoid materials with varying thickness and properties. The thickness of the thin film greatly affects the graphitizability and properties of the material. In situ current annealing inside a TEM reveals that thin samples form large graphene layers parallel to the substrate, while thick samples form multi-walled cage-like structures. MD simulations show that carbonized layers align parallel to the surface for films with a thickness below 40 angstrom, and become increasingly misoriented for thicker samples.
MACROMOLECULAR MATERIALS AND ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Maximilian Kolhep, Florian Pantle, Monika Karlinger, Di Wang, Torsten Scherer, Christian Kuebel, Martin Stutzmann, Margit Zacharias
Summary: We demonstrate the epitaxial coating of GaN NWs with an epitaxial ZnO shell by atomic layer deposition. Scanning transmission electron microscopy confirms a sharp and defect-free coherent interface. The strain in the core-shell structure was analyzed using 4D-STEM strain mapping and Raman spectroscopy, and compared to theoretical calculations. The results highlight the advantages of epitaxial shell growth using atomic layer deposition, such as conformal coating and precise thickness control.
Article
Microscopy
Sangjun Kang, Di Wang, Christian Kuebel, Xiaoke Mu
Summary: Transmission electron microscopy is a valuable tool for assessing strain fields within materials. However, using thin specimens in TEM analysis can affect atomic configuration and deformation structure.