Article
Multidisciplinary Sciences
Kwanghwi Je, Sangmin Lee, Erin G. Teich, Michael Engel, Sharon C. Glotzer
Summary: The research investigates the entropically driven growth of colloidal dodecagonal quasicrystals (DQCs) through computer simulations, showing that soft-matter quasicrystals dominated by entropy can be thermodynamically stable and grown with high structural quality, similar to their alloy quasicrystal counterparts.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Materials Science, Multidisciplinary
Jinjia Zhang, Yashushi Kamimura, Yuki Tokumoto, Keiichi Edagawa
Summary: In this study, the presence of phonon-phason coupling in an Al-Pd-Mn icosahedral quasicrystal is demonstrated using a new experimental method. The coupling strength is quantitatively evaluated by comparing the induced phason strain with theoretical values. The study discusses the origin of an internal friction peak observed previously and the potential effects of the coupling on the onset of phasonic elastic instability.
PHILOSOPHICAL MAGAZINE
(2022)
Article
Materials Science, Multidisciplinary
Jinjia Zhang, Jintao Zhou, Yuki Tokumoto, Keiichi Edagawa
Summary: The elasticity of quasicrystals is characterized by a unique term, phonon-phason coupling, which is absent in conventional crystals and remains an important subject in quasicrystals research. A novel method was recently applied to a Mackay-type icosahedral quasicrystal to prove the existence of phonon-phason coupling and evaluate its strength. In this study, the method was applied to a Tsai-type icosahedral system to evaluate its phonon-phason coupling strength. By inducing phason strain using phonon strain and detecting it with powder X-ray diffraction, the phonon-phason coupling constant of the Ag-In-Yb quasicrystal was evaluated to be 0.17 +/- 0.04 GPa through quantitative comparison with calculation results.
MATERIALS TRANSACTIONS
(2023)
Article
Multidisciplinary Sciences
Shinji Watanabe
Summary: Quasicrystals have unique lattice structures and rotational symmetries that differ from periodic crystals. The electric state and physical property of quasicrystals are not yet fully understood. Recent discovery of ferromagnetic long-range order in rare-earth-based quasicrystals has provided new insights into their magnetic dynamics.
SCIENTIFIC REPORTS
(2022)
Article
Materials Science, Multidisciplinary
Alok Singh, Takanobu Hiroto, Machiko Ode, Hiroyuki Takakura, Karel Tesar, Hidetoshi Somekawa, Toru Hara
Summary: The precipitation of a stable quasicrystalline i-phase has been observed in a Mg-6Zn-3Al magnesium alloy, which may be the first discovery of a stable i-phase in this alloy. The dissolution of i-phase at grain boundaries leads to precipitation in the Mg-matrix during cooling. Nucleation characteristics, phase transformation, and interface morphology were investigated.
Article
Multidisciplinary Sciences
Eva G. Noya, Chak Kui Wong, Pablo Llombart, Jonathan P. K. Doye
Summary: The study introduces a class of IQCs built from model patchy colloids, which could be realized experimentally using DNA origami particles. The rational design strategy leads to systems that robustly assemble into target IQCs through directional bonding.
Article
Multidisciplinary Sciences
Shinji Watanabe
Summary: Quasicrystals possess a unique lattice structure without translational invariance, and recent research has revealed the structure and dynamics of the ferromagnetic hedgehog state in the icosahedral quasicrystal. The study shows that the magnetic excitation mode exhibits streak fine structure in the q-energy plane, characteristic of the hedgehog state in the icosahedral quasicrystal.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Multidisciplinary
Ryo Takeuchi, Farid Labib, Takafumi Tsugawa, Yuto Akai, Asuka Ishikawa, Shintaro Suzuki, Takenori Fujii, Ryuji Tamura
Summary: We discovered a tunable and high-purity ferromagnetic Au-Ga-Dy icosahedral quasicrystal. The isothermal magnetization of the polycrystalline ferromagnetic i QC was studied, revealing its mean-field-like behavior during the ferromagnetic transition. Additionally, we found that the maximum Weiss temperature (θp) of the i QCs occurred at the electrons-per-atom (e/a) ratio of 1.70, demonstrating the tunability of the magnetic properties of i QCs based on the θp - e/a scheme for the first time. This work provides direct evidence that the magnetism of i QCs depends on the e/a ratio or the Fermi energy, opening avenues for future exploration of exotic magnetic textures on quasiperiodic lattices through the e/a ratio.
PHYSICAL REVIEW LETTERS
(2023)
Article
Multidisciplinary Sciences
Shinji Watanabe
Summary: In quasicrystals, the crystalline electric field of rare-earth elements plays a key role in the unique magnetic textures and topological states, which can be manipulated by controlling the compositions of non-rare-earth elements in the compounds.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Manufacturing
C. Galera-Rueda, M. L. Montero-Sistiaga, K. Vanmeensel, M. Godino-Martinez, J. Llorca, M. T. Perez-Prado
Summary: In-depth characterization of the microstructure of Al7075 SLM processed samples has revealed the occurrence of icosahedral quasicrystal-enhanced nucleation during laser fabrication. This solidification mechanism, along with the presence of twin boundaries and specific orientation symmetry in ultrafine grains, demonstrates the wide range of possibilities for novel physical metallurgy phenomena and advanced metal design offered by additive manufacturing methods.
ADDITIVE MANUFACTURING
(2021)
Article
Materials Science, Multidisciplinary
Shuai Zhang, Qianqian Li, Hongcan Chen, Qun Luo, Qian Li
Summary: In this study, the Mg40Zn55Nd5 icosahedral quasicrystal (I-phase) structure was observed in an as-cast Mg-58Zn-4Nd alloy using high-resolution electron microscopy. The thermodynamic stability of the quasicrystal was investigated and it was found to decompose into other phases after annealing.
INTERNATIONAL JOURNAL OF MINERALS METALLURGY AND MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
C. Galera-Rueda, X. Jin, J. LLorca, M. T. Perez-Prado
Summary: This work provides clear evidence for the occurrence of icosahedral quasicrystal enhanced nucleation during selective laser melting of gas atomized commercially-pure Ni powders. The study reveals the solidification of grains of the primary phase on the facets of iQCs formed due to the presence of icosahedral short range order in the liquid. Additionally, this work highlights the importance of additive manufacturing methods in investigating solidification fundamentals and designing unprecedented grain boundary networks.
SCRIPTA MATERIALIA
(2022)
Article
Multidisciplinary Sciences
Aviram Uri, Sergio C. de la Barrera, Mallika T. Randeria, Daniel Rodan-Legrain, Trithep Devakul, Philip J. D. Crowley, Nisarga Paul, Kenji Watanabe, Takashi Taniguchi, Ron Lifshitz, Liang Fu, Raymond C. Ashoori, Pablo Jarillo-Herrero
Summary: Researchers have created a highly tunable quasicrystal structure by twisting three layers of graphene and forming two mutually incommensurate moire patterns. This 'moire quasicrystal' allows for control over the electronic system between periodic and quasiperiodic regimes, and exhibits superconductivity and flavour-symmetry-breaking phase transitions.
Article
Crystallography
Bo Zhang, Honghang Tu, Liangjuan Li, Jiangong Yu, Jun Dai
Summary: In this study, the propagation and optimization of Rayleigh waves in a functionally graded one-dimensional hexagonal quasicrystal half-space are investigated using the analytical Laguerre orthogonal polynomial method. The effects of phonon-phason coupling, inhomogeneity, and quasiperiodic direction on wave characteristics are analyzed, leading to some new findings. These results provide a theoretical foundation for the design and optimization of SAW devices.
Article
Physics, Condensed Matter
R. M. Khusnutdinoff, R. R. Khairullina, A. A. Suslov, V. Lad'yanov, A. Mokshin
Summary: This study reveals the presence of icosahedral short-range order in nickel melts, which can transform into clusters with a fcc/hcp symmetry through a "liquid-crystal" phase transition. It also highlights the inadequacy of the Voronoi tessellation method in correctly identifying the distorted icosahedral short-range order in metal melts.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
