Topologically protected states of matter are receiving widespread attention owing to their unusual electronic properties Using numerical simulations, this study predicts that tin telluride is a physical realization of a new class of materials termed topological crystalline insulators

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Topological crystalline insulators in the SnTe material class

Topological insulators represent a new quantum state of matter which is characterized by peculiar edge or surface states that show up due to a topological character of the bulk wave functions. This review presents a pedagogical account on topological insulator materials with an emphasis on basic theory and materials properties. After presenting a historical perspective and basic theories of topological insulators, it discusses all the topological insulator materials discovered as of May 2013, with some illustrative descriptions of the developments in materials discoveries in which the author was involved. A summary is given for possible ways to confirm the topological nature in a candidate material. Various synthesis techniques as well as the defect chemistry that are important for realizing bulk-insulating samples are discussed. Characteristic properties of topological insulators are discussed with an emphasis on transport properties. In particular, the Dirac fermion physics and the resulting peculiar qu...

http://inspirehep.net/record/1229385/files/arXiv:1304.5693.pdf

Topological Insulator Materials

We show that the Raman scattering technique can give complete structural information for one-dimensional systems, such as carbon nanotubes. Resonant confocal micro-Raman spectroscopy of an (n,m) individual single-wall nanotube makes it possible to assign its chirality uniquely by measuring one radial breathing mode frequency omega(RBM) and using the theory of resonant transitions. A unique chirality assignment can be made for both metallic and semiconducting nanotubes of diameter d(t), using the parameters gamma(0) = 2.9 eV and omega(RBM) = 248/d(t). For example, the strong RBM intensity observed at 156 cm(-1) for 785 nm laser excitation is assigned to the (13,10) metallic chiral nanotube on a Si/SiO2 surface.

Structural (n,m) determination of isolated single wall carbon nanotubes by resonant Raman scattering

Topological insulators represent a new quantum state of matter which is characterized by peculiar edge or surface states that show up due to a topological character of the bulk wave functions. This review presents a pedagogical account on topological insulator materials with an emphasis on basic theory and materials properties. After presenting a historical perspective and basic theories of topological insulators, it discusses all the topological insulator materials discovered as of May 2013, with some illustrative descriptions of the developments in materials discoveries in which the author was involved. A summary is given for possible ways to confirm the topological nature in a candidate material. Various synthesis techniques as well as the defect chemistry that are important for realizing bulk-insulating samples are discussed. Characteristic properties of topological insulators are discussed with an emphasis on transport properties. In particular, the Dirac fermion physics and the resulting peculiar quantum oscillation patterns are discussed in detail. It is emphasized that proper analyses of quantum oscillations make it possible to unambiguously identify surface Dirac fermions through transport measurements. The prospects of topological insulator materials for elucidating novel quantum phenomena that await discovery conclude the review.

With the arising of global climate change and resource shortage, in recent years, increased attention has been paid to environmentally friendly materials. Trees are sustainable and renewable materials, which give us shelter and oxygen and remove carbon dioxide from the atmosphere. Trees are a primary resource that human society depends upon every day, for example, homes, heating, furniture, and aircraft. Wood from trees gives us paper, cardboard, and medical supplies, thus impacting our homes, school, work, and play. All of the above-mentioned applications have been well developed over the past thousands of years. However, trees and wood have much more to offer us as advanced materials, impacting emerging high-tech fields, such as bioengineering, flexible electronics, and clean energy. Wood naturally has a hierarchical structure, composed of well-oriented microfibers and tracheids for water, ion, and oxygen transportation during metabolism. At higher magnification, the walls of fiber cells have an interes...

https://www.fpl.fs.fed.us/documnts/pdf2016/fpl_2016_zhu001.pdf

Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications.

Effect of carbon nanotube length on thermal, electrical and mechanical properties of CNT/bismaleimide composites

We studied the use of carbon-nanotube- (CNT)-based strain sensors as components of a textile-based, wearable sensing system for real-time motion detection. In the stretchable sensor, millimeter-long multiwalled CNTs (MWCNTs) are unidirectionally aligned and sandwiched between elastomer layers. We synthesized urethane resin to make the elastomer, which exhibits low elasticity and an affinity for human skin. The aligned CNT layer was formed by stacking CNT webs drawn from a spinnable CNT forest. The stretchable sensor can be stretched up to 200% and exhibits a short sensing delay of less than 15 ms. The gauge factor exceeds 10, which indicates high sensitivity. Moreover, the device is thin and as soft as human skin. The demonstrated flexibility and conformable nature make this material ideally suited for wearable sensors, specifically for a textile-based, wearable, real-time, human body motion-sensing application.

Rapid-Response, Widely Stretchable Sensor of Aligned MWCNT/Elastomer Composites for Human Motion Detection

We found the easy and efficient synthesis method of the vertically aligned ultralong multiwalled nanotubes using iron chloride powder. The 2.1-mm-long bulk nanotubes can be grown by conventional thermal chemical vapor deposition on bare quartz surface with the single gas flow of acetylene for 20min. In addition to the high growth rate, the bulk of carbon nanotubes is easily spun into the yarn by pulling it out, and the present method also provides the coating ability with nanotubes as a new functionality of this nanomaterial.

Yoku Inoue

Papers

Effect of carbon nanotube length on thermal, electrical and mechanical properties of CNT/bismaleimide composites

Rapid-Response, Widely Stretchable Sensor of Aligned MWCNT/Elastomer Composites for Human Motion Detection

One-step grown aligned bulk carbon nanotubes by chloride mediated chemical vapor deposition

Anisotropic carbon nanotube papers fabricated from multiwalled carbon nanotube webs

Mechanical and electrical property improvement in CNT/Nylon composites through drawing and stretching