Phys.org April 22, 2024 Refractory alloys are very resistant to heat and wear but are not ductile or resistant to fracture. A team of researchers in the US (UC Berkeley, Lawrence Berkeley National Laboratory, UC Irvine, Pacific Northwest National Laboratory) examined the strength and fracture toughness of the Single-phase body-centered cubic (bcc) refractory alloy, NbTaTiHf, from 77 to 1473 kelvin. Whereas the glide and intersection of screw and mixed dislocations promoted strain hardening controlling uniform deformation, the coordinated slip of <111> edge dislocations with {110} and {112} glide planes prolonged nonuniform strain through formation of kink bands. These bands suppressed […]
Scientists develop novel liquid metal alloy system to synthesize diamond under moderate conditions
Phys.org April 24, 2024 There is an existing model that diamond can be grown using liquid metals only at both high pressure and high temperature. Researchers in South Korea described the growth of diamond crystals and polycrystalline diamond films with no seed particles using liquid metal but at 1 atm pressure and at 1,025 °C. Diamond grew in the subsurface of liquid metal composed of gallium, iron, nickel and silicon, by catalytic activation of methane and diffusion of carbon atoms into and within the subsurface regions. They found that the supersaturation of carbon in the liquid metal subsurface led to the nucleation […]
Scientists find novel one-dimensional superconductor
Nanowerk April 24, 2024 Extensive efforts have been undertaken to combine superconductivity and the quantum Hall effect so that Cooper-pair transport between superconducting electrodes in Josephson junctions is mediated by one-dimensional edge states. So far it has proven challenging to achieve detectable supercurrents through quantum Hall conductors. An international team of researchers (UK, South Korea, Spain, Japan, USA – Yale University) showed that domain walls in minimally twisted bilayer graphene support exceptionally robust proximity superconductivity in the quantum Hall regime, allowing Josephson junctions to operate in fields close to the upper critical field of superconducting electrodes. The critical current was […]
Smart fabrics that cancel noise and sculpt sound
Nanowerk April 23, 2024 A team of researchers in the US (MIT, University of Wisconsin–Madison, Case Western University) investigated traditional fabrics as emitters and suppressors of sound. They found that when attached to a single strand of a piezoelectric fiber actuator, silk fabric emits up to 70 dB of sound. Despite the complex fabric structure, vibrometer measurements revealed behavior reminiscent of a classical thin plate. Fabric pore size relative to the viscous boundary layer thickness was found to influence acoustic-emission efficiency. They demonstrated sound suppression using two distinct mechanisms – direct acoustic interference where sound reduced by up to 37 […]
Spintronics: A new path to room temperature swirling spin textures
Science Daily April 17, 2024 In spintronics the generation and stabilization of most of the magnetic textures is restricted to a few materials and achievable under very specific conditions (temperature, magnetic field…). Recently, a new approach has shown potential for the imprint of magnetic radial vortices in soft ferromagnetic compounds making use of the stray field of YBa2Cu3O7-δ superconducting microstructures in ferromagnet/superconductor (FM/SC) hybrids at temperatures below the superconducting transition temperature (TC). Using a new approach an international team of researchers (France, Spain, Germany) explored the lower size limit for the imprint of magnetic radial vortices in square and disc […]
Spintronics research shows material’s magnetic properties can predict how a spin current changes with temperature
Phys.org April 23, 2024 An international team of researchers (Japan, Australia) examined magnon spin currents in the ferrimagnetic garnet Tb3Fe5O12 with 4f electrons through the spin-Seebeck effect and neutron scattering measurements. The compound showed a magnetic compensation, where the spin-Seebeck signal reversed above and below K. Unpolarized neutron scattering unveiled two major magnon branches with finite energy gaps which were well explained in the framework of spin-wave theory. Their temperature dependencies and the direction of the precession motion of magnetic moments defined using polarized neutrons explained the reversal at and decay of the spin-Seebeck signals at low temperatures. According to […]
Top 10 Science and Technology Inventions for the Week of April 19, 2024
01. A universal path for converting light into current in solids 02. Discovery of organic catalyst could lead to cheaper fuel cells 03. Internet can achieve quantum speed with light saved as sound 04. A magnetic nanographene butterfly poised to advance quantum technologies 05. ‘Surprising’ hidden activity of semiconductor material spotted by researchers 06. Combating disruptive ‘noise’ in quantum communication 07. Researchers control quantum properties of 2D materials with tailored light 08. Quantum precision: A new kind of resistor 09. Defect removal of 2D semiconductor crystals 10. The experimental demonstration of a verifiable blind quantum computing protocol And others Cloud […]
Cloud engineering could be more effective ‘painkiller’ for global warming than previously thought
Phys.org April 11, 2024 Marine cloud brightening is a proposed method to tackle warming through injecting aerosols into marine clouds. However, it is unclear how aerosols influence clouds. An international team of researchers (USA – University of Birmingham, NASA GSFC, Greenbelt, MD, University of Maryland Baltimore County, UK, Switzerland) used satellite observations of volcanic eruptions in Hawaii to quantify the aerosol fingerprint on tropical marine clouds. They observed a large enhancement in reflected sunlight, mainly due to an aerosol-induced increase in cloud cover. This suggested that the current level of global warming is driven by a weaker net radiative forcing […]
Combating disruptive ‘noise’ in quantum communication
Phys.org April 15, 2024 Nonlocality is crucial for device-independent technologies like quantum key distribution and randomness generation. It quickly deteriorates in the presence of noise, and restoring nonlocal correlations requires additional resources incurring a significant resource overhead. An international team of researchers (Australia, France, USA – NIST, Boulder, CO) experimentally demonstrated that single copies of Bell-local states, incapable of violating any standard Bell inequality, could give rise to nonlocality after being embedded into a quantum network of multiple parties. They subjected the initial entangled state to a quantum channel that broadcast part of the state to two independent receivers and […]
Defect removal of 2D semiconductor crystals
Nanowerk April 11, 2024 The exact role of h-BN encapsulation in relation to the internal defects of 2D semiconductors in hexagonal boron nitride (h-BN) remains unclear. An international team of researchers (South Korea, Japan) reported that h-BN encapsulation greatly removes the defect-related gap states by stabilizing the chemisorbed oxygen molecules onto the defects of monolayer tungsten disulfide (WS2) crystals. Studies showed that h-BN encapsulation prevented the desorption of oxygen molecules over various excitation and ambient conditions, resulting in a greatly lowered and stabilized free electron density in monolayer WS2 crystals. This suppressed the exciton annihilation processes by two orders of […]