Researchers at NIST have recently built the first low-energy focused ion beam (FIB) microscope that uses a lithium ion source. Although the new microscope's resolution isn't yet as good as a scanning electron microscope or a helium ion microscope (HIM), it can image nonconductive materials and can more clearly visualize the chemical composition on the surface of a sample than the higher-energy SEMs and FIBs.
Researchers from the NIST Center for Nanoscale Science and Technology have observed electromagnetically induced transparency at room temperature and atmospheric pressure in a silicon nitride optomechanical system. This work highlights the potential of silicon nitride as a material for producing integrated devices in which mechanical vibrations can be used to manipulate and modify optical signals.
Researchers at JILA in Colorado have engineered a short, flexible, reusable probe for the atomic force microscope (AFM) that enables state-of-the-art precision and stability in picoscale force measurements. Shorter, softer and more agile than standard and recently enhanced AFM probes, the JILA tips will benefit nanotechnology and studies of folding and stretching in biomolecules such as proteins and DNA.
As a planet orbits, its gravity makes its parent star wobble a tiny bit, resulting in slight color changes in the star's light due to the Doppler effect. A high-quality reference spectrum allows scientists to make a comparison to find planets. Now, NIST has made extensive new measurements of thorium, a heavy element often used in emission lamps that help provide that fixed ruler. The work has more than doubled the number of spectral lines.
Researchers at NIST have devised an idea for determining the 3-D shape of features as small as 10-nm wide. The model-based method compares data from scanning electron microscope images with stored entries in a library of 3-D shapes to find a match and to determine the shape of the sample. The work provides a powerful new way to characterize nanostructures.
Over the first six months in their special, new, four-bedroom home in suburban Maryland, the Nisters, a prototypical family of four, earned about $40 by exporting 328 kW-h of electricity into the local grid, while meeting all of their varied energy needs. These virtual residents of the Net-Zero Energy Residential Test Facility (NZERTF) on the campus of NIST didn't have to skimp the creature comforts of 21st century living, either.
Researchers have applied a novel microscopy technique to characterize metal-organic framework (MOF) materials, potentially opening a pathway for engineering the chemical properties of these materials at the nanoscale. MOFs are composed of metal ions connected by organic linker molecules to form 3-D-crystalline networks of nanopores with high surface areas, leading to applications in catalysis, chemical separation and sensing.
JILA physicists used an ultrafast laser and help from German theorists to discover a new semiconductor quasiparticle, a handful of smaller particles that briefly condense into a liquid-like droplet. Quasiparticles are composites of smaller particles that can be created inside solid materials and act together in a predictable way.
Researchers from NIST and the FDA have demonstrated that they can make sensitive chemical analyses of minute samples of nanoparticles by, essentially, roasting them on top of a quartz crystal. The NIST-developed technique, "microscale thermogravimetric analysis," holds promise for studying nanomaterials in biology and the environment, where sample sizes often are quite small and larger-scale analysis won't work.
While pursuing the goal of turning a cloud of ultracold atoms into a completely new kind of circuit element, physicists at NIST have demonstrated that such a cloud, known as a Bose-Einstein condensate, can display a sort of "memory." The findings pave the way for a host of novel devices based on "atomtronics," an emerging field that offers an alternative to conventional electronics.
It's not quite Star Trek communications—yet. But long-distance communications in space may be easier now that researchers have designed a clever detector array that can extract more information than usual from single particles of light. Described in a new paper, the NIST/JPL array-on-a-chip easily identifies the position of the exact detector in a multi-detector system that absorbs an incoming infrared light particle, or photon.
Researchers at NIST have developed a new method for accurately measuring a key process governing a wide variety of cellular functions that may become the basis for a health checkup for living cells. The NIST technique measures changes in a living cell's internal redox (reduction-oxidation) potential, a chemistry concept that expresses the favorability of reactions in which molecules or atoms either gain or lose electrons.
NIST and American Univ. researchers report in a new study that the bench-scale test widely used to evaluate whether a burning cigarette will ignite upholstered furniture may underestimate the tendency of component materials to smolder when these materials are used in sofas and chairs supported by springs or cloth. The study comes as regulations and methods for evaluating ignition in furniture are undergoing scrutiny.
Shape is thought to play an important role in the effectiveness of cells grown to repair or replace damaged tissue in the body. To help design new structures that enable cells to "shape up," researchers at NIST have come up with a way to measure, and more importantly, classify, the shapes cells tend to take in different environments.
A team NIST scientists, with collaborators elsewhere, has achieved a five-fold reduction in the dominant uncertainty in an experiment that measured the mean lifetime of the free neutron, resulting in a substantial improvement of previous results. However, the accomplishment reveals a puzzling discrepancy when compared to different method, and researchers are planning to re-run the experiment in upgraded form.
Researchers at NIST and in Lithuania have used a NIST-developed laboratory model of a simplified cell membrane to accurately detect and measure a protein associated with a serious gynecological disease, bacterial vaginosis (BV), at extraordinarily low concentrations. The work illustrates how the artificial membrane could be used to improve disease diagnosis.
Though piezoelectrics are a widely used technology, there are major gaps in our understanding of how they work. Researchers at NIST and in Canada believe they've learned why one of the main classes of these materials, known as relaxors, behaves in distinctly different ways from the rest and exhibit the largest piezoelectric effect. And the discovery comes in the shape of a butterfly.
Heralding a new age of terrific timekeeping, a research group led by a NIST physicist has unveiled an experimental strontium atomic clock that has set new world records for both precision and stability—key metrics for the performance of a clock. The JILA strontium lattice clock is about 50% more precise than the record holder of the past few years, NIST’s quantum logic clock.
Computer scientist Yi-Kai Liu at NIST has devised a way to make a security device that has proved notoriously difficult to build: a "one-shot" memory unit, whose contents can be read only a single time. The innovation, which uses qubits and conjugate coding, shows in theory how the laws of quantum physics could allow for the construction of such memory devices.
Using an approach akin to assembling a club sandwich at the nanoscale, NIST researchers have succeeded in crafting a uniform, multi-walled carbon nanotube-based coating that greatly reduces the flammability of foam commonly used in upholstered furniture and other soft furnishings. The flammability of the nanotube-coated polyurethane foam was reduced 35% compared with untreated foam.
Modern epoxies are frequently made stronger, lighter and more resilient with the addition of multiwalled carbon nanotubes (MWCNTs), a special form of carbon that under a microscope looks like rolls of chicken wire. Few analytical methods have been employed, however, to determine the effect this material has on environmental or health safety. NIST has developed a suite of tests for evaluating the performance of these nanocomposite materials.
Are electrons truly round? More specifically, is the electron’s charge between its poles uniform? A group at JILA has tackled this difficult question and has developed a method of spinning electric and magnetic fields around trapped molecular ions to measure the tiny electrons. They haven’t yet matched other electric dipole moment measurement techniques, but eventually the new method should surpass them.
Scientists from NIST and Sandia National Laboratories have added something new to a family of engineered, high-technology materials called metal-organic frameworks (MOFs): the ability to conduct electricity. This breakthrough—conductive MOFs—has the potential to make these already remarkable materials even more useful, particularly for detecting gases and toxic substances.
Researchers from the NIST Center for Nanoscale Science and Technology (CNST) have demonstrated a new low-energy electron beam technique and used it to probe the nanoscale electronic properties of grain boundaries and grain interiors in cadmium telluride (CdTe) solar cells. Their results suggest that controlling material properties near the grain boundaries could provide a path for increasing the efficiency of such solar cells.
A consortium led by Northwestern Univ. will establish a new NIST-sponsored center of excellence for advanced materials research. The Center for Hierarchical Materials Design (CHiMaD) will be funded in part by a $25 million award from NIST over five years and will focus on computational tools, databases and experimental techniques to allow “materials by design”, a major goal of the Materials Genome Initiative.