Discover Top Posts Tagged with #borides

New class of strong magnets uses earth-abundant elements, avoids rare-earth metals

Georgetown University researchers have discovered a new class of strong magnets that do not rely on rare-earth or precious metals—a breakthrough that could significantly advance clean energy technologies and consumer electronics such as motors, robotics, MRI machines, data storage and smart phones. A key figure of merit for a magnet is the ability of its magnetization to strongly prefer a specific direction, known as magnetic anisotropy, which is a cornerstone property for modern magnetic technologies. Today, the strongest anisotropy materials for permanent magnets depend heavily on rare-earth elements, which are expensive, environmentally damaging to mine and vulnerable to supply-chain disruptions and geopolitical instability. For thin film applications, certain alloys of iron and platinum have become the materials of choice for next generation magnetic recording media, which contain precious metal platinum. Finding high-performance alternatives based on earth-abundant elements has therefore been a long-standing scientific and technological challenge.

New rocket fuel compound packs 150% more energy

University at Albany chemists have created a new high-energy compound that could revolutionize rocket fuel and make space flights more efficient. Upon ignition, the compound releases more energy relative to its weight and volume compared to current fuels. In a rocket, this would mean less fuel required to power the same flight duration or payload and more room for mission-critical supplies. Their study was published in the Journal of the American Chemical Society. "In rocket ships, space is at a premium," said Assistant Professor of Chemistry Michael Yeung, whose lab led the work. "Every inch must be packed efficiently, and everything onboard needs to be as light as possible. Creating more efficient fuel using our new compound would mean less space is needed for fuel storage, freeing up room for equipment, including instruments used for research. On the return voyage, this could mean more space is available to bring samples home."

A New Superhard Material

Planting vacancies into the atomic lattice of a brittle material increases its toughness and hardness. [...] Superhard materials like diamond are useful for industrial cutting tools but are expensive, so researchers have been searching for alternatives. Unfortunately, hard materials are often brittle. Now Shanmin Wang of the Southern University of Science and Technology in China and his colleagues have created a superhard but nonbrittle material by adding vacancies to the atomic lattice [1]. Wang says that the technique could be applied to other materials. The mechanical properties of metals and alloys depend heavily on defects in their crystal lattices called dislocations. These are lines along which a plane of atoms comes to a sudden end. When a crystal is stressed, atomic bonds break and reform in a way that can cause a dislocation to move perpendicular to the planes. This ability for dislocations to “slide” allows metals to deform without breaking, but it also reduces a material’s rigidity and hardness. Treatments that prevent dislocation sliding can increase hardness but also brittleness.

Researchers have discovered a new 2D material, confirming decade-old prediction.

More than ten years ago, researchers at Rice University led by materials scientist Boris Yakobson predicted that boron atoms would cling too tightly to copper to form borophene, a flexible, metallic two-dimensional material with potential across electronics, energy and catalysis. Now, new research shows that prediction holds up, but not in the way anyone expected. Unlike systems such as graphene on copper, where atoms may diffuse into the substrate without forming a distinct alloy, the boron atoms in this case formed a defined 2D copper boride -- a new compoundwith a distinct atomic structure. The finding, published in Science Advances by researchers from Rice and Northwestern University, sets the stage for further exploration of a relatively untapped class of 2D materials.

Advanced tungsten-based ceramics achieve high hardness and ablation resistance

A research team successfully synthesized tungsten carbide (WC) and tungsten boride (WB2) ceramics with excellent mechanical properties and ablation resistance. These findings were published in the journal of Ceramics International and Journal of the European Ceramic Society. The team was led by Prof. Huang Zhulin at the Institute of Solid State Physics, the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, Ultrahigh temperature ceramics (UHTCs) are essential materials for thermal protection systems with high melting points and excellent stability. Tungsten-based UHTCs offer excellent resistance to heat and radiation. However, they have faced several challenges in practical applications, such as difficulty in achieving high density during processing, grain coarsening during sintering, and limited oxidation and ablation resistance.

Ceramic powders with Archimedean shapes resist extreme heat and oxidation

A research team led by Prof. Hu Xiaoye from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has synthesized high-quality boride ceramic powders with an Archimedean shape. These findings, published in the Journal of the European Ceramic Society, hold promising implications for the future of heat protection materials. Boride ceramics are renowned for their high melting points, excellent oxidation resistance, and outstanding corrosion resistance, making them ideal candidates for heat-resistant materials. However, the synthesis of high-performance boride ceramic composites has remained a significant challenge, particularly in producing high-purity powders.

Computational method discovers hundreds of new ceramics for extreme environments

If you have a deep-seated, nagging worry over dropping your phone in molten lava, you're in luck. A research team led by materials scientists at Duke University has developed a method for rapidly discovering a new class of materials with heat and electronic tolerances so rugged that they could enable devices to function at lava-like temperatures above several thousands of degrees Fahrenheit. Harder than steel and stable in chemically corrosive environments, these materials could also form the basis of new wear- and corrosion-resistant coatings, thermoelectrics, batteries, catalysts, and radiation-resistant devices. The recipes for these materials—ceramics made using transition metals carbonitrides or borides—were discovered through a new computational method called Disordered Enthalpy-Entropy Descriptor (DEED). In its first demonstration, the program predicted the synthesizability of 900 new formulations of high-performance materials, 17 of which were then tested and successfully produced in laboratories.

Molybdenum boride ceramics developed for harsh environment SERS detection

A research team has successfully synthesized three different crystalline phases of molybdenum boride with a strong Raman signal enhancement performance. These findings were published in the journal of Small. The researchers were led by Prof. Huang Zhulin at the Institute of Solid State Physics, Hefei Institutes of Physical Science of the Chinese Academy of Sciences, along with researchers from the University of Massachusetts Amherst. Surface-enhanced Raman scattering (SERS) is a rapid and non-destructive detection method widely used in various fields including trace pollutant monitoring, food safety, chemical catalysis, and molecular fingerprint identification. However, most noble metal SERS materials are costly and exhibit poor physical and chemical stability, especially under extreme conditions such as high temperatures and strong corrosive environments, where SERS enhancement effect diminishes rapidly.

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