Articles tagged with "thermal-conductivity"
3x more efficient: Metallic material with highest thermal conductivity identified
Researchers at UCLA Samueli School of Engineering have identified theta-phase tantalum nitride (θ-TaN) as a metallic material with the highest thermal conductivity measured among metals, conducting heat nearly three times more efficiently than copper or silver. This discovery challenges previous assumptions about the limits of heat transport in metals, where copper has long been the standard with a thermal conductivity of about 400 W/m·K. The team experimentally realized single-crystalline θ-TaN, measuring a room-temperature thermal conductivity of approximately 1100 W/m·K. This exceptional performance is attributed to the material’s unique atomic structure—tantalum and nitrogen atoms arranged in a hexagonal pattern—which leads to a distinctive phonon band structure that suppresses phonon-phonon scattering and exhibits weak electron-phonon coupling. The findings, published in the journal Science, have significant implications for thermal management in electronics, particularly as AI technologies and high-performance computing systems increasingly demand efficient heat dissipation to prevent overheating and maintain reliability. Currently
materialsthermal-conductivitytantalum-nitrideheat-dissipationelectronic-devicesthermal-managementmetalsAt atomic scale, diamonds can briefly trap heat in unexpected ways, transform quantum tech
Scientists at the University of Warwick have discovered that at the atomic scale, diamonds can briefly trap heat around specific atomic defects, creating unexpected “hot spots.” This finding challenges the conventional view of diamond as the world’s best thermal conductor. The team studied a nitrogen-hydrogen defect in diamond (Ns:H-C0) using ultrafast infrared laser pulses and advanced multidimensional coherent spectroscopy (2DIR). Instead of immediate heat dissipation, the defect entered a transient “hot ground state,” where vibrational energy accumulated locally, shifting the defect’s infrared signature for a few picoseconds before decaying. This localized heating occurs because the defect emits high-energy phonons—vibrations that move slowly and scatter quickly—forming a tiny heat bubble that delays energy transfer to the broader diamond lattice. Such momentary local heating is significant because atomic-scale defects are sensitive quantum systems whose stability and precision depend on their environment. The findings have important implications for diamond-based quantum technologies, including ultra-precise sensors and quantum
materialsquantum-technologydiamond-defectsthermal-conductivityphononsspectroscopynanotechnologyUS lab heats up advanced nuclear reactor fuel testing for critical performance
Lightbridge Corporation has initiated irradiation testing of its enriched uranium-zirconium alloy fuel samples at the Advanced Test Reactor (ATR) within Idaho National Laboratory (INL). This marks a critical transition from manufacturing to active performance evaluation under a Cooperative Research and Development Agreement with INL. The testing aims to gather essential data on the fuel alloy’s microstructural changes and thermal conductivity as a function of burnup, which are key parameters for qualifying and licensing the fuel for commercial nuclear reactor use. Throughout the campaign, irradiated samples will be periodically extracted for post-irradiation examination at INL to assess the fuel’s behavior over time. This detailed analysis will validate the thermo-mechanical properties of the fuel alloy and support Lightbridge’s goal of deploying the advanced fuel in existing and new water-cooled reactors. The testing follows successful prior technical milestones, including the co-extrusion manufacturing process of the fuel samples, which involved encasing a uranium-zirconium billet within zirconium alloy cladding
energynuclear-reactoradvanced-materialsfuel-testinguranium-zirconium-alloyirradiation-testingthermal-conductivityScientists discover boron arsenide beats diamond in heat transfer
Researchers at the University of Houston have discovered that boron arsenide (BAs), a synthetic crystal, surpasses diamond in thermal conductivity, achieving values above 2,100 W/mK at room temperature. This finding challenges the long-held belief that diamond is the best isotropic heat conductor and suggests that existing theoretical models need revision, as previous calculations—factoring in four-phonon scattering—had capped BAs’s conductivity at 1,360 W/mK. The breakthrough was made possible by producing ultra-pure BAs crystals through refined synthesis techniques, overcoming limitations caused by impurities in earlier samples. Beyond its record-breaking heat conduction, boron arsenide also exhibits promising semiconductor properties, including a wider band gap, higher carrier mobility, and compatibility with chip integration due to its thermal expansion coefficient. These combined attributes make BAs a strong candidate to outperform silicon in electronics, offering potential improvements in thermal management for devices ranging from smartphones to data centers and high-performance computing systems. Supported by a National
materialsboron-arsenidethermal-conductivitysemiconductor-materialsheat-transferelectronics-coolingadvanced-materialsNew carbon nanotube insulation can resist temperatures exceeding 4,700°F
Chinese researchers at Tsinghua University have developed a novel carbon nanotube-based insulation film capable of withstanding temperatures up to 4,712°F (2,600°C), significantly surpassing the limits of conventional insulators that typically fail above 2,732°F (1,500°C). This ultralight, porous, multilayered material is made by growing vertical carbon nanotube arrays and drawing them into thin sheets, which are then stacked or wound into layers. The structure effectively blocks all three modes of heat transfer—solid conduction, gas conduction, and radiative heat transfer—by exploiting the nanotubes’ nanoscale dimensions, pore size, and unique electronic properties that absorb and scatter infrared radiation. The new insulation exhibits an exceptionally low thermal conductivity of 0.004 W/mK at room temperature and 0.03 W/mK at 2,600°C, outperforming common high-temperature insulators like graphite felt, which has a thermal conductivity of 1.6 W/m
materialscarbon-nanotubeshigh-temperature-insulationthermal-conductivityaerospace-materialsenergy-applicationsnanotechnologySilica from meteorites may hold key to controlling industrial heat
Researchers at Columbia University have identified a unique form of silicon dioxide called tridymite, originally found in meteorites and also present on Mars, which exhibits hybrid crystal-glass thermal properties. Unlike typical materials where thermal conductivity either decreases (crystals) or increases (glasses) with temperature, tridymite maintains a nearly constant thermal conductivity over a wide temperature range (80 K to 380 K). This discovery was made possible by applying a unified equation for heat conduction in both crystals and glasses, developed by Professor Michele Simoncelli’s team using machine learning to overcome computational challenges. Experimental validation was conducted on a tridymite sample from a 1724 meteorite found in Germany, confirming its intermediate atomic structure and stable heat conduction behavior. This breakthrough has significant implications for industrial heat management, particularly in sectors like electronics, aerospace, and steel manufacturing. For instance, tridymite could form in refractory bricks used in steel furnaces after prolonged thermal aging, potentially enabling more efficient heat control and reducing the
materialsthermal-conductivitysilicon-dioxidetridymiteheat-managementcrystal-glass-hybridaerospace-materialsUS engineer spins bacteria into strong plastic-like eco-sheets
A team led by Maksud Rahman, assistant professor at the University of Houston, has developed a novel single-step method to grow biodegradable bacterial cellulose sheets that are strong enough to rival conventional plastics. By using a custom rotational culture device that guides bacterial motion through controlled fluid flow, the researchers produced aligned cellulose nanofibers, resulting in flexible, strong, and multifunctional sheets. These sheets have potential applications ranging from packaging and medical dressings to textiles and green electronics, offering an eco-friendly alternative to petroleum-based plastics. The innovation also includes enhancing the bacterial cellulose by incorporating boron nitride nanosheets into the nutrient solution, creating hybrid composites with significantly improved properties such as tensile strength up to 553 MPa and thermal conductivity three times higher than untreated samples. Published in Nature Communications, this scalable, bottom-up biosynthesis approach leverages biological processes combined with mechanical design, avoiding energy-intensive manufacturing typical of traditional bioplastics. The team envisions widespread adoption of this sustainable material across various industries aiming to
materialsbiodegradable-plasticsbacterial-cellulosenanofiberseco-friendly-materialscomposite-materialsthermal-conductivityBiodegradable cooling film slashes energy use 20% without power
Scientists from Zhengzhou University and the University of South Australia have developed the world’s first biodegradable cooling film capable of passively reducing surface temperatures by up to 9.2°C without electricity. Made from polylactic acid (PLA), a plant-based biodegradable plastic, the film achieves this cooling by reflecting 98.7% of solar radiation and enabling internal heat to radiate directly into outer space. This passive cooling effect can reduce energy consumption for air conditioning by more than 20% in hot urban environments, offering a sustainable alternative to conventional, energy-intensive cooling systems. The metafilm features a porous, bi-continuous structure with ultra-low thermal conductivity (0.049 W/m·K) and high durability, maintaining performance even after exposure to harsh acid solutions and prolonged UV radiation. Its robustness is attributed to a 29.7% stereocomplex crystal content, which enhances thermal and chemical stability. Computer simulations indicate significant potential energy savings in cities like Lhasa, China, and the technology
energybiodegradable-materialscooling-filmpassive-coolingsustainable-technologypolylactic-acidthermal-conductivity