Research For Our Energy Future

Complex Materials

Unusual properties may lead to new superconductors

Page 2 of 2

BNL Researchers

Brookhaven Lab superconducting cable researchers: (from left) Vyacheslav Solovyov, Department of Condensed Matter Physics & Materials Science (CMPMS ); and Tom Muller, Physics Department.

Featured Publication:

Electron Pairing in High-Temperature Superconductors

Other Materials

In addition to high-Tc superconductors, scientists at Brookhaven are studying a range of other potentially useful complex materials. These include:

Tools of the Trade

To investigate the properties of complex materials, Brookhaven scientists employ a suite of high-tech tools and techniques.

Electron photoemission spectroscopy: At the National Synchrotron Light Source (NSLS ), a source of high-intensity light at various wavelengths, scientists use beams of visible light to “kick” electrons off their sample materials and measure the electrons’ properties to reveal how their interactions with the sample changed them. This gives information about the material’s overall electronic structure.

X-ray scattering: Performed at the NSLS and elsewhere, but this time using beams of x-rays, which scatter off the sample. Changes in the rays’ energy and momentum reveal details about the ordering of complex materials.

Neutron scattering: Similar to x-ray scattering, only using beams of neutrons. Performed at neutron facilities around the country, including the National Institute for Standards and Technology and the Spallation Neutron Source at Oak Ridge National Laboratory. This technique provides information on the magnetic and charge ordering.

Scanning tunneling microscopy: Uses a probe to allow electrons to flow either into or out of a material to give information about the electronic structure at a particular “real-space” point on the sample.

Electron microscopy: Uses high-energy electrons as a beam to scatter off the material’s crystal lattice. Techniques include real-space imaging, electron-energy loss spectroscopy, and phase-sensitive microscopy to provide insight into the structure of complex materials with atomic resolution.

High-temperature Superconducting Material

Scanning tunneling microscope image of high-temperature superconducting material.

Materials Synthesis

An important key to advancing complex materials is a strong capability in materials synthesis. Brookhaven has a wide array of advanced synthesis capabilities. For example, a unique molecular beam epitaxy system developed at the Lab enables layer-by-layer synthesis of atomically smooth films as well as multilayers with perfect interfaces. Using this device, Brookhaven researchers recently produced two-layer thin films where neither layer is superconducting on its own, but which exhibit a nanometer-thick region of superconductivity at their interface. These materials might be useful in devices such as superconductive transistors and eventually in ultrafast, power-saving electronics. The technology may also help improve the ability of layered superconductors to carry super-current between layers.

Other Brookhaven researchers have become experts in growing single crystals of complex high-Tc materials, supplying researchers at Brookhaven and other research institutions with samples for their studies. Such high-quality, single crystals are at the very heart of scientific research successes in the field of condensed matter experimental physics.

There are also important economic reasons for being on the cutting-edge of new-materials design: Applications tend to be developed in close proximity to the innovators, so nations that discover new materials stand to benefit by being first to market. Right now, the U.S. is behind several countries in new-materials development. Brookhaven scientists hope to do their part to change that.

Let it Flow

The development of superconductors that could be used in real-world applications, particularly power transmission, could transform the U.S. energy landscape. In addition to huge cost-savings, the higher capacity enabled by superconducting cables would help overcome urban power bottlenecks in today’s power grid, reducing the potential for blackouts and other power interruptions. It would also improve the cost-effective control of power flowing across the national grid and extend the operating life of existing high-load power lines. Furthermore, zero-loss transmission would enable the transfer of solar energy generated in parts of the U.S. where sunlight is most abundant to those where it is not, thus making other energy-saving technologies more practical and affordable.

Last Modified: November 6, 2009