MANA E-BULLETIN VOL.06
Advanced nano-fabrication technology catalyzing discovery and innovation at MANA
Manager of the Namiki Foundry, MANA
Facilities for lithography and nanofabrication were established at NIMS in 2004 under the leadership of Masakazu Aono, the Director the International Center for Materials Nanoarchitectonics (WPI-MANA) at NIMS from 2007 to 2017. The facilities became a part of WPI-MANA in 2009 and are now referred to as the Namiki Foundry.
Photonic Circuits Hosting Electromagnetic Waves with Pseudospin
Metamaterials are purposely built devices mimicking structural features of normal materials, but with unusual physical properties. Photonic crystals, for example, are periodic nanostructures consisting of material components with different refractive indices. They have lattice symmetries like solids, but the constituents of the unit cell of a photonic crystal are ‘bits’ of the different bulk materials. Similar to the structure–property relationships resulting from the behavior of electrons in solids (e.g. semiconduction), photonic crystals offer ways for manipulating the propagation of light. Now, Xiao Hu at the International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan, and colleagues have succeeded in creating a photonic metamaterial that displays a special property known as a topological photonic state.
Y. Li et al., “Topological LC-circuits based on microstrips and observation of electromagnetic modes with orbital angular momentum”, Nat. Comms. 9, 4598 (2018).
Origins of Macroscopic Friction Linked to Energy Landscape on the Nanoscale
Everybody is familiar with friction — the phenomenon plays an important role in our daily lives. Yet, although phenomenological laws exist that describe friction on the macroscale, a detailed understanding of the processes involved on the microscale is lacking. Now, Hiroshi Sakuma and Shigeru Suehara (the International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan) with their colleagues have studied friction forces in mica, both theoretically and experimentally, and have found the origin of molecular friction in this system.
H. Sakuma et al., “What is the origin of macroscopic friction?”, Science Advances 4, eaav2268 (2018)
Porous Structure of a Layered Silicate with Selective Adsorption Properties Revealed
It is not always easy to precisely determine the crystal structure of layered materials — but in order to fully understand and exploit their properties, detailed structural information is needed. Magadiite is such a layered material, used as an adsorbent and a catalyst. It is known that magadiite is a kind of layered silicates: tetrahedra, each with oxygen atoms at the vertices and a silicon atom in the center, grouped in planar arrangements. The precise structure, however, was not known — partly because the material typically occurs as small lamellas displaying poor crystallinity — until now. Satoshi Tominaka at the International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Japan, and colleagues have succeeded in determining the crystal structure of magadiite. Based on their structural insights, Yusuke Ide (MANA, NIMS) and colleagues also managed to explain why the material has outstanding photocatalytic properties and proved its application in the synthesis of pure benzoic acid from toluene using a photocatalyst system.
Y. Ide, Satoshi Tominaka et al., “Zeolitic intralayer microchannels of magadiite, a natural layered silicate, to boost green organic synthesis”, Chem. Sci.9, 8637 (2018).
The International Center for Materials Nanoarchitectonics
1-1 Namiki Tsukuba-shi Ibaraki, 305-0044 JAPAN
SOURCE The International Center for Materials Nanoarchitectonics