Science Daily December 15, 2018 An international team of researchers (USA – MIT, Lawrence Berkeley National Laboratory, UC Berkeley, US Army, China) used gelatin hydrogel as a scaffold to coordinate metal ions (Mo5+, W6+, Co2+), resulting in ultrathin‐film morphologies of diverse TMC sheets. Among these materials, the Mo2C–Co hybrid provides excellent hydrogen evolution reaction (HER) efficiency. Such performance makes Mo2C–Co a viable noble‐metal‐free catalyst for the HER and is competitive with the standard platinum on carbon support. This template‐assisted, self‐assembling, scalable, and low‐cost manufacturing process presents a new tactic to construct low‐dimensional TMCs with applications in various clean‐energy‐related fields…read more. […]
Tag Archives: Materials science
Imperfections make photons perfect for quantum computing
Nanowerk December 17, 2018 Researchers at Rice University found that in molybdenum disulfide a dash of rhenium in just the right spot makes a configuration of atoms with energy states that sit comfortably inside and are isolated from the material’s natural band gap. Aligning magnetic moments of atoms in the defect and exciting them with light brings them to a higher energetic state making them exit as single photon. The direction of the photon is not understood, but the researchers suspect that it is well defined. The defect’s optical transition lies in the optical fiber telecommunication band, which is ideal […]
The feature size and functional range of molecular electronic devices
Eurekalert December 14, 2018 Knowing the feature size of the domination of tunneling leakage in molecular electronics is of fundamental significance, which enhances the understanding of the technical limitations and boundaries for using single-molecule components as electronic devices. An international team of researchers (China, UK, Switzerland) investigated the transition distance between through-space tunneling and molecular tunneling using the oligo(aryleneethynylene) molecules. They demonstrated that molecular tunneling can be distinguished and outstripped from the tunneling leakage down to the size of 0.66 nm, suggesting the potential to push the miniaturization limit of molecular electronic devices to the angstrom scale…read more. TECHNICAL ARTICLE
Data use draining your battery? Tiny device to speed up memory while also saving power
Eurekalert December 13, 2018 In RRAM, an electrical current is typically driven through a memory cell made up of stacked materials creating a change in resistance that records data as 0s and 1s in memory. A material would need to be robust enough for storing and retrieving data at least trillions of times. A team of researchers in the US (Purdue University, NIST, industry) found that in Molybdenum ditelluride when an electric field is applied to the cell, atoms are displaced by a tiny distance resulting in a state of high resistance which can occur much faster than switching in conventional […]
Environment turns molecule into a switch
Phys.org November 26, 2018 An international team of researchers (Germany, Spain) used a manganese phthalocyanine molecule, which cannot be normally switched, and mounted it on a metallic surface built of silver and bismuth atoms. When a very fine tip emitting an electric field approached the manganese atom at the centre of the molecule, the molecule took on two stable switchable states. They demonstrated that this functionality can also be created in non-switchable molecules by selectively manipulating the molecule’s environment developing a new concept to build molecular switches which may open new design possibilities in molecular electronics in the future…read more. […]
Self-sensing materials are here
Nanowerk November 16, 2018 In Carbon fiber composites the damage can remain hidden below the surface, undetectable by visual inspection. Researchers at the Oak Ridge National Laboratory have invented a roll-to-roll process to coat electrically conductive carbon fibers with semiconducting silicon carbide nanoparticles. This nanomaterial-embedded composite is stronger than other fiber-reinforced composites and imbued with a new capability—the ability to monitor its own structural health…read more. TECHNICAL ARTICLE
New insulating state found in stretched graphene
Nanowerk November 9, 2018 Using quantum simulation methods that model electron interactions explicitly, an international team of researchers (Italy, Japan) has found that when stretched graphene transitions to a more exotic nonmagnetic topological state called a Kekulé-like dimerized nonmagnetic insulator which could have interesting technological applications. They intend to find out more about the nature of the phase transition between electrons…read more. TECHNICAL ARTICLE
Making steps toward improved data storage
Phys.org November 7, 2018 Researchers in Japan developed a terahertz pulse generator that delivered ultra-short and highly intense terahertz pulses across a pair of gold antennas. The pulses created an electric field in the material composed of germanium, antimony and tellurium (GST) sample, comparable to that of an electrically switched device. It greatly reduced the heat diffusion because of the extremely short duration of terahertz pulses enabling fine control over the rate and direction of GST crystallization. After a certain point when terahertz pulses were increased, crystal conductivity rapidly sped up instead of rising in line with the increase in […]
Uncovering secret structure to explosives
Lawrence Livermore National Laboratory October 17, 2018 In most high explosives, detonation is initiated through a process where pores get compressed by a shockwave. Researchers at the Lawrence Livermore National Laboratory found that in an explosive compound called HMX when pores are at the surface, they speed up the reaction, if a shockwave hits a number of surface pores at once, they bootstrap each other. While they showed that many small pores can work together to accelerate one another’s burning, they also were able to identify a threshold where pores become so small that the reaction is extinguished. This examination […]
Researchers switch material from one state to another with a single flash of light
SLAC National Accelerator Laboratory October 19,2018 In tantalum disulfide the charge density waves are all oriented in the same direction in the alpha state. A team of researchers in the US (MIT, SLAC National Accelerator, Harvard University) zapped a thin crystal of tantalum disulfide with a very brief laser pulse. They found that some of the waves flipped into a beta state with a different electron orientation, and the alpha and beta regions were separated by domain walls. A second flash of light dissolved the domain walls and returned the material to its pure alpha state. They could fine-tune the […]