A team of researchers from the Royal Institute of Technology, Stockholm, the University of Maryland, and NIST have measured large variations in the magnetic properties along the edge of a thin-film 500-nm-diameter disk. This work represents a significant development in the measurement of magnetic thin-film edge properties, which are especially important for nanodevices, such as magnetic memory cells, where the edge to area ratio is large.
Using a low-cost apparatus designed to quickly and accurately measure the properties of handheld laser devices, NIST researchers tested 122 laser pointers and found that nearly 90% of green pointers and about 44% of red pointers tested were out of compliance with federal safety regulations. The NIST test apparatus was designed so that it can be replicated easily by other institutions.
Using a low-cost apparatus designed to quickly and accurately measure the properties of handheld laser devices, NIST researchers tested 122 laser pointers and found that nearly 90% of green pointers and about 44% of red pointers tested were out of compliance with federal safety regulations. Often, these pointers emitted more visible power than allowed by law
Efforts to eliminate contamination has allowed users of scanning electron microscopes (SEMs) to measure the exact features of a sample, not the sample features plus a layer of contamination. But contamination persists, which is why researchers at NIST are working to elevate microscope accuracy by eliminating the gradual buildup of carbonaceous material on a sample, introduced by the action of the charged particle beam.
Researchers at NIST have developed a new microscope able to view and measure an important but elusive property of the nanoscale magnets used in an advanced, experimental form of digital memory. The new instrument already has demonstrated its utility with initial results that suggest how to limit power consumption in future computer memories.
One of the oldest forms of computer memory is back again—but in a 21st century microscopic device designed by physicists at NIST for possible use in a quantum computer. The NIST team has demonstrated that information encoded as a specific point in a traveling microwave signal—the vertical and horizontal positions of a wave pattern at a certain time—can be transferred to the mechanical beat of a microdrum and later retrieved with 65% efficiency, a good figure for experimental systems like this.
Scientists in Maryland have built a new practical, high-efficiency nanostructured electron source. Unlike thermionic electron sources, which use an electric current to boil electrons off the surface of a wire, the new emitter uses highly porous silicon carbide to avoid the energy efficiency problems of traditional emitters. This type of field emitter has a fast response and could lead to improved X-ray imaging systems.
Tiny biomolecular chambers called nanopores that can be selectively heated may help doctors diagnose disease more effectively if recent research by a team at NIST proves effective. The team has pioneered work on the use of nanopores for the detection and identification of a wide range of molecules, including DNA. These nanopores mimic ion channels, the gateways by which a cell admits and expels materials.
Researchers at the NIST have demonstrated a solid-state refrigerator that uses quantum physics in micro- and nanostructures to cool a much larger object to extremely low temperatures. What's more, the prototype NIST refrigerator, which measures a few inches in outer dimensions, enables researchers to place any suitable object in the cooling zone and later remove and replace it, similar to an all-purpose kitchen refrigerator.
While infrared (IR) microscopy has been used since the 1950s to determine the chemical composition of materials, the spatial resolution of the technique has been limited to tens of micrometers. Researchers at NIST and the University of Maryland have overcome this limitation, demonstrating that a new spectroscopy technique can simultaneously measure a material's topography and chemical composition with nanometer-scale spatial resolution.
One of the surprising predictions of quantum mechanics is that uncharged conductors can attract each other over small distances, even in empty space. While the resulting “Casimir force” has been accurately measured and calculated for simple flat conductors, researchers have solved the much more complicated problem of calculating this force between metal plates with complicated periodic nanoscale structures on their surfaces.
A new guide for Web developers recently released by NIST will make it easier for electric utilities and vendors to give customers convenient, electronic access to their energy usage data with tools and applications developed as part of the new "Green Button" initiative.
The first fruits of a cooperative venture between scientists at Rice University and NIST have appeared in a paper that brings together a wealth of information for those who wish to use the unique properties of metallic carbon nanotubes. The article gathers research about the separation and fundamental characteristics of armchair carbon nanotubes, which have been of particular interest to researchers trying to tune their electronic and optical properties.
NIST has demonstrated a novel chip-scale instrument made of carbon nanotubes that may simplify absolute measurements of laser power, especially the light signals transmitted by optical fibers in telecommunications networks. The prototype device, a miniature version of an instrument called a cryogenic radiometer, is a silicon chip topped with circular mats of carbon nanotubes standing on end.
A team of researchers at NIST has shown that by bringing gold nanoparticles close to the dots and using a DNA template to control the distances, the intensity of a quantum dot's fluorescence can be predictably increased or decreased. This breakthrough opens a potential path to using quantum dots as a component in better photodetectors, chemical sensors, and nanoscale lasers.
Researchers from the NIST Center for Nanoscale Science and Technology and Johns Hopkins University have developed a technique to reliably manipulate hundreds of individual micrometer-sized colloid particles to create crystals with controlled dimensions. The accomplishment is an important milestone for understanding how to direct and control the assembly of microscale and nanoscale objects for nanomanufacturing applications.
The NIMS International Center for Materials Nanoarchitectonics has developed a supermolecular material which makes it possible to visualize the distribution of cesium on the surface of solids and in living organisms by fluorescence.
Having blood drawn and analyzed to diagnose disease is a process that can take a few days, but what if your doctor could perform this analysis in moments, right before your eyes? That's the promise of "lab-on-a-chip" technology, and researchers are working on a variety of fronts to remove technical roadblocks. A new idea addresses the issue of sensor shelf life, showing how some such chips might be made to last for months or more until needed.
Communicating with light may soon get a lot easier, hints recent research from NIST and the University of Maryland's Joint Quantum Institute (JQI), where scientists have potentially found a way to overcome a longstanding barrier to cleaner signals.
An international collaboration of researchers has demonstrated the ability to make photons emitted by quantum dots at different frequencies identical to each other by shifting their frequencies to match. This "quantum frequency conversion" is an important step for making solid-state, single photon sources, including quantum dots, more useful light sources for photonic quantum information science.
A research team including scientists from NIST has confirmed long-standing suspicions among physicists that electrons in a crystalline structure called a kagome lattice can form a "spin liquid," a novel quantum state of matter in which the electrons' magnetic orientation remains in a constant state of change.
Evaporative cooling has long been used to cool atoms, but it has never before been done by molecules—two different atoms bonded together. Achieving a goal considered nearly impossible, JILA physicists have done this, chilling a gas of molecules to very low temperatures by adapting the familiar process by which a hot cup of coffee cools.
A research group at NIST has developed a relatively simple, fast, and effective method of depositing uniform, ultrathin layers of platinum atoms on a surface. The new process exploits an unexpected feature of electrodeposition of platinum—if you drive the reaction much more strongly than usual, a new reaction steps in to shuts down the metal deposition process, allowing an unprecedented level of control of the film thickness.
Scientists at NIST have devised and demonstrated a novel method for making the most precise measurements to date of the properties of two atomic transitions in rubidium, and element whose transitions are used as frequency standards for many atomic clocks. The technique is accurate to about 0.3%, which is 10 times more accurate than the best theoretical values.
Using an enhanced form of "chemical microscopy" developed at NIST, researchers there have shown that they can peer into the structure of blended polymers, resolving details of the molecular arrangement at sub-micrometer levels. The capability has important implications for the design of industrially important polymers like the polyethylene blends used to repair aging waterlines.