decagonal quasicrystals

decagonal quasicrystals
Name	Decagonal quasicrystals
Caption	Electron diffraction pattern showing tenfold symmetry
Category	Quasicrystalline materials
Discovered	1980s
Examples	Al–Co–Ni, Al–Cu–Co, Mg–Zn–Y
Symmetry	Tenfold rotational, quasiperiodic in plane, periodic along one axis
Applications	Surface coatings, photonic devices, catalysis

decagonal quasicrystals are a class of aperiodic solids exhibiting tenfold rotational symmetry in two dimensions and periodic order along a perpendicular axis. First identified in the wake of discoveries that challenged classical crystallography, they bridge concepts from Shechtman-era quasicrystalline research to modern materials science initiatives at institutions such as IBM and Bell Labs. Research into their structure and properties has engaged laboratories at Oak Ridge National Laboratory, Los Alamos National Laboratory, and universities including MIT, Stanford University, University of Cambridge, and University of Tokyo.

Introduction

Decagonal quasicrystals were initially observed in alloys such as Al–Co–Ni and Al–Cu–Co and later in systems including Mg–Zn–Y and Zn–Mg–Ho, prompting theoretical and experimental efforts at organizations like Argonne National Laboratory, Lawrence Berkeley National Laboratory, Max Planck Society, and CNRS. Key contributors include researchers affiliated with Technion, University of Pennsylvania, University of California, Berkeley, Tohoku University, and University of Oxford. Developments intersect with advances in electron microscopy at Hitachi, synchrotron studies at European Synchrotron Radiation Facility, and neutron scattering at ISIS Neutron and Muon Source.

Structure and Symmetry

The decagonal phase exhibits quasiperiodicity in a plane with exact tenfold rotational symmetry and crystallographic periodicity along the stacking axis, a structural motif analyzed using higher-dimensional crystallography pioneered by scholars associated with Bragg Institute, Royal Society, and National Academy of Sciences. Models employ projection methods from a five-dimensional hyperlattice, approaches developed in collaboration between groups at University of Vienna, University of Paris, and Princeton University. Atomic decorations often follow Penrose-like tilings, motifs linked historically to mathematics from Roger Penrose and geometric studies at Institute for Advanced Study. Structural refinements have been performed using data from teams at European Molecular Biology Laboratory, Max Planck Institute for Metals Research, and Rutherford Appleton Laboratory.

Formation and Synthesis

Decagonal phases form by rapid solidification, annealing, or vapor deposition in alloy systems investigated by researchers at NASA, European Space Agency, and industrial labs such as Siemens and General Electric. Synthesis protocols include melt spinning developed at Carnegie Mellon University, sputter deposition refined at Hitachi, and molecular beam epitaxy techniques practiced at IBM Research. Thermomechanical processing studies have been conducted at Argonne National Laboratory and Fraunhofer Society facilities to control phase selection and grain orientation.

Physical and Chemical Properties

These quasicrystals display anisotropic transport, low thermal conductivity, and high surface hardness, properties characterized by groups at Los Alamos National Laboratory, Sandia National Laboratories, and National Institute of Standards and Technology. Electronic properties have been probed in collaborations with CERN, NIST, and Tokyo Institute of Technology using spectroscopy methods from teams at Max Planck Institute for Solid State Research and Harvard University. Surface chemistry for catalytic and corrosion-resistant roles has been studied by researchers at Scripps Research Institute, Columbia University, and University of Illinois Urbana-Champaign.

Phase Stability and Thermodynamics

Phase diagrams and thermodynamic stability windows for decagonal alloys are mapped using calorimetry and computational thermodynamics by groups at Imperial College London, ETH Zurich, University of Michigan, and Ohio State University. First-principles calculations and molecular dynamics simulations have been carried out by teams at Lawrence Livermore National Laboratory, Los Alamos National Laboratory, and Sandia National Laboratories using methods advanced at Princeton Plasma Physics Laboratory and Caltech. Experimental assessments of metastability and solid-state transformations involve high-temperature furnaces at National Renewable Energy Laboratory and quenching facilities at Oak Ridge National Laboratory.

Characterization Techniques

High-resolution transmission electron microscopy and selected-area electron diffraction, employed by groups at JEOL, Hitachi, University of Cambridge, and University of Oxford, are central to confirming tenfold symmetry. Synchrotron X-ray diffraction studies conducted at Diamond Light Source, Advanced Photon Source, and SPring-8 support refinements, while neutron scattering experiments at Institut Laue–Langevin and SNS probe dynamics. Surface-sensitive tools like scanning tunneling microscopy developed at IBM and angle-resolved photoemission spectroscopy teams at SLAC National Accelerator Laboratory elucidate electronic states. Computational structure analysis leverages software and algorithms from projects at Los Alamos National Laboratory, National Center for Supercomputing Applications, and Barcelona Supercomputing Center.

Applications and Technological Implications

Applications explored by industrial partners including Siemens, General Electric, and Toyota involve wear-resistant coatings, thermal barriers, and low-friction surfaces. Photonic and plasmonic device concepts leveraging quasiperiodic order have been proposed by research groups at MIT, Caltech, EPFL, and University of Toronto. Potential roles in catalysis and hydrogen storage are under investigation at Brookhaven National Laboratory, Argonne National Laboratory, and Pacific Northwest National Laboratory. Cross-disciplinary initiatives link to programs at DARPA, European Commission, and National Science Foundation, reflecting interest across materials science hubs such as Kavli Institute for Theoretical Physics and Weizmann Institute of Science.

Category:Quasicrystals