Thin films are ubiquitous in computer chips and other electronic devices. Researchers have recently begun tuning the properties of these films by growing them on substrates with different crystal structures. A particularly interesting case is the lanthanum-cobalt oxide, LaCoO3, or LCO for short. As a bulk crystal, LCO is not magnetic, but thin films of LCO grown on certain substrates exhibit ferromagnetic ordering. Previous attempts to explain this induced magnetism have been unable to incorporate the fact that the atomic arrangement, or crystal symmetry, of epitaxial LCO film is distinct from that of both its bulk phase and its substrates. This symmetry mismatch leads to additional structural distortions in LCO thin films, as observed in x-ray experiments performed at the U.S. Department of Energy’s Advanced Photon Source (APS) and elsewhere.
Humans can learn a lot from plants. With energy from the sun, protein catalysts in plants efficiently split water to generate oxygen, storing the energy as carbohydrates. Scientists would like to perform a similar trick, using solar energy to split water and produce hydrogen fuel. Hydrogen fuel burns clean, producing only water as a byproduct, but splitting water is not an efficient task for humans. Researchers have taken baby steps toward artificial photosynthesis, building solar-powered water-splitting catalysts in the laboratory, but so far these catalysts remain far less efficient than their vegetal counterparts. One reason it's difficult to improve catalytic efficiency is that scientists don't fully understand the catalysts’ water-splitting mechanism.
Researchers utilizing intense x-ray beams from the U.S. Department of Energy’s Advanced Photon Source (APS) examined the flow of electricity through semiconductors and uncovered another reason these materials seem to lose their ability to carry a charge as they become more densely “doped.” Their results, which may help engineers design faster semiconductors in the future, were published online in the journal ACS Nano.
10-ID-B, 11-ID-D, 12-ID-B
"Frustration" plus a pulse of laser light resulted in a stable "supercrystal" created by a team of researchers from two U.S. universities and three U.S. Department of Energy national laboratories, including Argonne National Laboratory.
7-ID-B,C,D, 11-ID-D, 33-BM-C, 33-ID-D,E
Developing hydrogen as a fuel is important for both economic and environmental reasons. This work carried out at the U.S. Department of Energy’s Advanced Photon Source advances our understanding of the charge-separation dynamics that occur in bio-inspired photocatalytic systems for the hydrogen evolution reaction.
Ultrafast X-rays Track Charge Flows in a Promising Photovoltaic Material: A class of materials known as lead halide perovskites show remarkable potential for use in optoelectronic applications. Experiments carried out at the U.S. Department of Energy’s Advanced Photon Source should improve the theoretical framework used to describe these materials, thereby hastening their practical use for solar power and other applications.
Laser Excitation Alters the Structure and Light Emission of Perovskite Thin Films: Hybrid organic-inorganic perovskites show exceptional promise for use in multiple optoelectronic applications. Research at the U.S. Department of Energy’s Advanced Photon Source produced dramatic results which provide important new insights into the dynamic behavior of these materials, which are being developed for advanced sensors, light-emitting diodes, and photovoltaic devices.
A team of researchers at the U.S. Department of Energy’s Argonne National Laboratory has developed another way of accessing ultrafast time scales by using microelectromechanical system (MEMS)-based photonic devices to achieve dynamic control of the hard x-ray pulses.
A team of researchers at the U.S. Department of Energy’s Argonne National Laboratory has developed another way of accessing ultrafast time scales by using microelectromechanical system-based photonic devices to achieve dynamic control of the hard x-ray pulses.
Scientists from the U.S. Department of Energy’s Advanced Photon Source have demonstrated a new research technique that address a broad range of questions concerning nanostructures of ultra-thin film that are an indispensable component of many electronic and photonic technologies.
Scientists using the U.S. Department of Energy's Advanced Photon Source show that hydrated starch granules mixed into conventional hydrogels can create tissue-like materials that could someday be used to create soft robots and biomedical implants with functionality beyond that of natural systems.
Tiny Chip-Based Device Performs Ultrafast Manipulation of X-Rays: Researchers from the U.S. Department of Energy’s Advanced Photon Source and Center for Nanoscale Materials have developed and demonstrated new x-ray optics that can be used to harness extremely fast pulses in a package that is significantly smaller and lighter than conventional devices used to manipulate x-rays.