Home > Press > NYU Physicists Find Way to Create Three-Dimensional Quasicrystals
Metallic quasicrystals created from exotic alloys have shown promise for storing hydrogen more efficiently than crystalline hosts
NYU Physicists Find Way to Create Three-Dimensional Quasicrystals
Sunnyvale, CA | July 11, 2005
New York University physicists have applied a ground-breaking nanotechnology method to create three-dimensional quasicrystals, highly ordered structures that, unlike conventional crystals, never repeat themselves.
Metallic quasicrystals created from exotic alloys have shown promise for storing hydrogen more efficiently than crystalline hosts. Their non-repeating structure has the potential to dramatically strengthen industrial and commercial products. The NYU quasicrystals, by contrast, are made of glass and plastic and have potentially revolutionary optical properties.
Holographic assembly of a three-dimensional colloidal quasicrystal. (a) Colloidal particles trapped in a two-dimensional projection of a three-dimensional icosahedral quasicrystalline lattice. (b) Particles displaced into the fully three-dimensional configuration. The shaded region identifies one embedded icosahedron. (c) Reducing the lattice constant creates a compact three-dimensional quasicrystal. (d) Optical diffraction pattern showing ten-fold symmetric peaks. The three-dimensional assembly process is shown in the associated movie.
Copyright © NYU
The research, authored by NYU physicists David Grier and Yael Roichman, appears in the July 11 issue of Optics Express, a journal of the Optical Society of America.
Quasicrystals, discovered in the mid-1980s, are different from crystals, whose periodic structures resemble the patterns of tiles on a bathroom floor. By contrast, quasicrystals do not have this property, called translational symmetry, but, like crystals, can be rotated into registry with themselves, a property called rotational symmetry.
Quasicrystals’ rotational symmetry gives them many of the properties of conventional crystals. These same symmetries are responsible for conventional semiconducting crystals’ ability to act as switches for electrons. However, because quasicrystals do not possess the translational symmetry of conventional crystals, they have the freedom to take a broader range of forms, opening up the potential to serve a range of functions.
The quasicrystals reported by Roichman and Grier are created from tiny glass spheres, each comparable in size to the wavelength of light, stacked precisely in mathematically defined configurations. Like the crystalline structures responsible for the irridescence of gem opals and the colors of butterfly wings, these quasicrystalline sphere packings diffract different wavelengths of light into different directions, creating a rainbow-like display. For particular structures, and particular wavelengths, however, the quasicrystals offer no path at all for light. The resulting gaps in the rainbow, known as photonic bandgaps, can be manipulated to create switches for light. For instance, when translated into structures with features comparable to the wavelength of light, these properties of quasicrystals should enable them to manipulate light in much the same way that semiconductors manipulate electrons.
This has already been achieved for two-dimensional structures by previous researchers. However, prior to the work of Roichman and Grier, scientists had not been able to branch out into three-dimensional quasicrystals - thereby reaping the full benefits of their unique properties - because of the inability to create this class of quasicrystals with the proper materials at the right size scale.
Previous attempts at addressing this challenge included the use of lithographic techniques. In a departure from this approach, Roichman, Grier, and their colleagues used a method developed by Grier’s group called holographic optical trapping. This allows scientists to manipulate objects as small as a few nanometers across and as large as several hundred micrometers. These “optical tweezers” allow scientists to organize microscopic objects into interesting and useful configurations, to dissect them, to assemble them into devices, or to chemically transform them, all with unprecedented precision. Using this method on quasicrystals, Roichman and Grier were able to organize hundreds of free-floating microspheres into densely packed structures defined by the mathematical definition of quasicrystalline order.
Grier is part of an NYU team of internationally recognized physicists in the field of soft condensed matter physics, a new inter-disciplinary field that explores how materials are organized at microscopic levels, and which studies the physical properties of malleable materials such as colloids and polymers. With Grier, Paul Chaikin, formerly of Princeton University, and David Pine, formerly of the University of California, Santa Barbara, form the core of NYU’s Center for Soft Matter Research. Yael Roichman is a postdoctoral researcher in Grier’s group.
Copyright © NYU
If you have a comment, please Contact
Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Conference speakers: International think tank needed to identify techno-social turning points December 6th, 2013
Bangalore INDIA NANO 2013 Inaugurated December 5th, 2013
3-D printing and custom manufacturing: from concept to classroom: Strategic investments from NSF help engineers revolutionize the manufacturing process December 5th, 2013
The promise of nanotechnology December 4th, 2013
The new stack type actuators series PA – more flexibility for your application December 13th, 2013
Iranian Scientists Discover New Electrical Device for Rapid Diagnosis of Cancer December 12th, 2013
3-D Analysis of Thermo-elastic Behavior of Composite Plate Graded with Carbon Nanotubes December 12th, 2013
Arrowhead to Report Fiscal 2013 Fourth Quarter and Year-End Financial Results - Conference Call Scheduled for Wednesday, December 18, 2013 December 12th, 2013
Quantum waves at the heart of organic solar cells December 12th, 2013
Research Team Finds Way to Make Solar Cells Thin, Efficient and Flexible December 11th, 2013
Nontoxic Quantum Dot Research Improves Solar Cells: Record power-conversion efficiency at Los Alamos from quantum-dot sensitized photovoltaics December 10th, 2013
New Method Presented for Production of Alpha SiAlON Single Phase Nanopowder December 10th, 2013