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Jang, Tae Jin (author), Lee, You Na (author), Ikeda, Yuji (author), Körmann, F.H.W. (author), Baek, Ju Hyun (author), Do, Hyeon Seok (author), Choi, Yeon Taek (author), Gwon, Hojun (author), Suh, Jin Yoo (author), Kim, Hyoung Seop (author), Lee, Byeong Joo (author), Zargaran, Alireza (author), Sohn, Seok Su (author)Complex concentrated alloys (CCAs) with a face-centered-cubic (FCC) structure exhibit remarkable mechanical properties, introducing the expansion of compositional space in alloy design for structural materials. The formation of a single solid-solution phase is enabled by configuring various 3d-transition elements, while doping other elements...journal article 2023
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Wissel, Kerstin (author), Riegger, Luise M. (author), Schneider, Christian (author), Waidha, Aamir I. (author), Famprikis, T. (author), Ikeda, Yuji (author), Grabowski, Blazej (author), Dinnebier, Robert E. (author), Lotsch, Bettina V. (author), Janek, Jürgen (author), Ensinger, Wolfgang (author), Clemens, Oliver (author)Solid-state batteries can be built based on thiophosphate electrolytes such as β-Li<sub>3</sub>PS<sub>4</sub>. For the preparation of these solid electrolytes, various solvent-based routes have been reported. For recycling of end-of-life solid-state batteries based on such thiophosphates, we consider the development of dissolution and...journal article 2023
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Wagner, Christian (author), Ferrari, A. (author), Schreuer, Jürgen (author), Couzinié, Jean Philippe (author), Ikeda, Yuji (author), Körmann, F.H.W. (author), Eggeler, Gunther (author), George, Easo P. (author), Laplanche, Guillaume (author)Physical properties of ten single-phase FCC Cr<sub>x</sub>Mn<sub>20</sub>Fe<sub>20</sub>Co<sub>20</sub>Ni<sub>40-</sub><sub>x</sub> high-entropy alloys (HEAs) were investigated for 0 ≤ x ≤ 26 at%. The lattice parameters of these alloys were nearly independent of composition while solidus temperatures increased linearly by ∼30 K as x increased...journal article 2022
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Chung, Hyun (author), Kim, Dae Woong (author), Cho, Woo Jin (author), Han, Heung Nam (author), Ikeda, Yuji (author), Ishibashi, Shoji (author), Körmann, F.H.W. (author), Sohn, Seok Su (author)High- and medium-entropy alloys (HEAs and MEAs) possess high solid-solution strength. Numerous investigations have been conducted on its impact on yield strength, however, there are limited reports regarding the relation between solid-solution strengthening and strain-hardening rate. In addition, no attempt has been made to account for the...journal article 2022
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Ikeda, Yuji (author), Gubaev, Konstantin (author), Neugebauer, Jörg (author), Grabowski, Blazej (author), Körmann, F.H.W. (author)Recent experiments show that the chemical composition of body-centered cubic (bcc) refractory high entropy alloys (HEAs) can be tuned to enable transformation-induced plasticity (TRIP), which significantly improves the ductility of these alloys. This calls for an accurate and efficient method to map the structural stability as a function of...journal article 2021
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Ikeda, Yuji (author), Körmann, F.H.W. (author)Interstitial alloying has become an important pillar in tuning and improving the materials properties of high-entropy alloys, e.g., enabling interstitial solid-solution hardening and for tuning the stacking fault energies. In this work we performed ab initio calculations to evaluate the impact of interstitial alloying with nitrogen on the fcc...journal article 2021
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Bannenberg, L.J. (author), Schreuders, H. (author), Kim, H.J. (author), Sakaki, Kouji (author), Hayashi, Shigenobu (author), Ikeda, Kazutaka (author), Otomo, Toshiya (author), Dam, B. (author), Asano, Kohta (author)Metal hydrides may play a paramount role in a future hydrogen economy. While most applications are based on nanostructured and confined materials, studies considering the structural response of these materials to hydrogen concentrate on bulk material. Here, using in situ in- and out-of-plane X-ray diffraction and reflectometry, we study the fcc ...journal article 2021
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Gubaev, Konstantin (author), Ikeda, Yuji (author), Tasnádi, Ferenc (author), Neugebauer, Jörg (author), Shapeev, Alexander V. (author), Grabowski, Blazej (author), Körmann, F.H.W. (author)An active learning approach to train machine-learning interatomic potentials (moment tensor potentials) for multicomponent alloys to ab initio data is presented. Employing this approach, the disordered body-centered cubic (bcc) TiZrHfTax system with varying Ta concentration is investigated via molecular dynamics simulations. Our results show...journal article 2021
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Yang, Dae Cheol (author), Jo, Yong Hee (author), Ikeda, Yuji (author), Körmann, F.H.W. (author), Sohn, Seok Su (author)Multi-principal element alloys usually exhibit outstanding strength and toughness at cryogenic temperatures, especially in CrMnFeCoNi and CrCoNi alloys. These remarkable cryogenic properties are attributed to the occurrence of deformation twins, and it is envisaged that a reduced stacking fault energy (SFE) transforms the deformation...journal article 2021
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Oh, Hyun Seok (author), Odbadrakh, Khorgolkhuu (author), Ikeda, Yuji (author), Mu, Sai (author), Körmann, F.H.W. (author), Sun, Cheng Jun (author), Ahn, Heh Sang (author), Yoon, Kook Noh (author), Ma, Duancheng (author), Tasan, Cemal Cem (author), Egami, Takeshi (author), Park, Eun Soo (author)Complex concentrated alloys (CCAs) are of growing interest due to their outstanding mechanical properties that exceed the property limits of conventional alloys. Whereas the superior properties are often attributed to severe lattice distortion, to date it is not clear what controls the lattice distortion and how it affects the mechanical...journal article 2021
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Rogal, Lukasz (author), Ikeda, Yuji (author), Lai, Minjie (author), Körmann, F.H.W. (author), Kalinowska, Alicja (author), Grabowski, Blazej (author)High entropy alloys (HEAs) in the hexagonal close-packed (hcp) phase usually show poor mechanical properties. We demonstrate here, by use of ab initio simulations and detailed experimental investigations, that the mechanical properties can be improved by optimizing the microstructure. In particular we design a dual-phase HEA consisting of a...journal article 2020
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Wu, Xiaoxiang (author), Li, Zhiming (author), Rao, Ziyuan (author), Ikeda, Yuji (author), Dutta, B. (author), Körmann, F.H.W. (author), Neugebauer, Jörg (author), Raabe, Dierk (author)We reveal the impact of magnetic ordering on stacking fault energy (SFE) and its influence on the deformation mechanisms and mechanical properties in a class of nonequiatomic quinary Mn-containing compositional complex alloys or high entropy alloys (HEAs). By combining ab initio simulation and experimental validation, we demonstrate magnetic...journal article 2020
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Saitoh, Kuniyasu (author), Hatano, Takahiro (author), Ikeda, Atsushi (author), Tighe, B.P. (author)We numerically investigate stress relaxation in soft athermal disks to reveal critical slowing down when the system approaches the jamming point. The exponents describing the divergence of the relaxation time differ dramatically depending on whether the transition is approached from the jammed or unjammed phase. This contrasts sharply with...journal article 2020
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Ishibashi, Shoji (author), Ikeda, Yuji (author), Körmann, F.H.W. (author), Grabowski, Blazej (author), Neugebauer, Jörg (author)Local lattice distortions in a series of body-centered cubic alloys, including refractory high-entropy alloys, are investigated by means of atomic volumes, atomic charges, and atomic stresses defined by the Bader charge analysis based on first-principles calculations. Analyzing the extensive data sets, we find large distributions of these...journal article 2020
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Guo, Wenqi (author), Su, Jing (author), Lu, Wenjun (author), Liebscher, Christian H. (author), Kirchlechner, Christoph (author), Ikeda, Yuji (author), Körmann, F.H.W. (author), Liu, Xuan (author), Xue, Yunfei (author), Dehm, Gerhard (author)In conventional metallic materials, strength and ductility are mutually exclusive, referred to as strength-ductility trade-off. Here, we demonstrate an approach to improve the strength and ductility simultaneously by introducing micro-banding and the accumulation of a high density of dislocations in single-phase high-entropy alloys (HEAs). We...journal article 2020
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Kies, Fabian (author), Ikeda, Yuji (author), Ewald, Simon (author), Schleifenbaum, Johannes H. (author), Hallstedt, Bengt (author), Körmann, F.H.W. (author), Haase, Christian (author)Density functional theory (DFT) calculations were performed on Al<sub>x</sub>C<sub>y</sub>CoFeMnNi multi-principal element alloys (MPEAs) to understand the influence of Al and C on the stacking-fault energy (SFE). C addition to CoFeMnNi resulted in increased SFE, while it decreased in Al-alloyed CoFeMnNi. For experimental verification, Al<sub...journal article 2020
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Ferrari, A. (author), Dutta, B. (author), Gubaev, Konstantin (author), Ikeda, Yuji (author), Srinivasan, P. (author), Grabowski, Blazej (author), Körmann, F.H.W. (author)The field of atomistic simulations of multicomponent materials and high entropy alloys is progressing rapidly, with challenging problems stimulating new creative solutions. In this Perspective, we present three topics that emerged very recently and that we anticipate will determine the future direction of research of high entropy alloys: the...journal article 2020
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Sohn, Seok Su (author), Kwiatkowski da Silva, Alisson (author), Ikeda, Yuji (author), Körmann, F.H.W. (author), Lu, Wenjun (author), Choi, Won Seok (author), Gault, Baptiste (author), Ponge, Dirk (author), Neugebauer, Jörg (author), Raabe, Dierk (author)Severe lattice distortion is a core effect in the design of multiprincipal element alloys with the aim to enhance yield strength, a key indicator in structural engineering. Yet, the yield strength values of medium- and high-entropy alloys investigated so far do not substantially exceed those of conventional alloys owing to the insufficient...journal article 2019
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Oh, Hyun Seok (author), Sang Jun, Kim (author), Odbadrakh, Khorgolkhuu (author), Ryu, Wook Ha (author), Yoon, Kook Noh (author), Mu, Sai (author), Körmann, F.H.W. (author), Ikeda, Yuji (author), Tasan, Cemal Cem (author), Raabe, Dierk (author), Egami, Takeshi (author), Park, Eun Soo (author)Quantitative and well-targeted design of modern alloys is extremely challenging due to their immense compositional space. When considering only 50 elements for compositional blending the number of possible alloys is practically infinite, as is the associated unexplored property realm. In this paper, we present a simple property-targeted...journal article 2019
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Rao, Ziyuan (author), Ponge, Dirk (author), Körmann, F.H.W. (author), Ikeda, Yuji (author), Schneeweiss, Oldřich (author), Friák, Martin (author), Neugebauer, Jörg (author), Raabe, Dierk (author), Li, Zhiming (author)To facilitate the understanding of Invar effects and design of FeNiCo-base Invar alloys characterized by low thermal expansion coefficient (TEC), we investigated the magnetic and thermal expansion behavior of an equiatomic prototype medium entropy alloy FeNiCo and a non-equiatomic (super Invar)Fe<sub>63</sub>Ni<sub>32</sub>Co<sub>5</sub> (at....journal article 2019