Nanowerk January 20, 2022 So far, only a few dozen 2D crystals have been extracted from materials that exhibit a layered phase in ambient conditions, omitting entirely the large number of layered materials that may exist at other temperatures and pressures. An international team of researchers (Austria, Germany, Slovakia, Belgium, France) synthesized 2D cuprous iodide that was stabilized in a graphene sandwich, as the first example of a material that does not otherwise exist in normal laboratory conditions. It normally only occurs in layered form at elevated temperatures between 645 and 675 K. The synthesis utilizes the large interlayer spacing […]
Category Archives: Materials science
Changing the properties of ferroelectric materials by vacating a single oxygen atom
Phys.org January 3, 2022 In ferroelectric materials, a slight shift of the atoms causes significant changes in the electric field and in the contraction or expansion of the material. An international team of researchers (Israel, USA – UCLA) succeeded in deciphering the atomic structure and electric field deployment in domain walls at the atomic scale. They corroborate the assumption that domain walls allow for the existence of a two-dimensional border between domains as a result of partial oxygen vacancy in areas that are common to two domains, thus enabling greater flexibility in the deployment of the local electric field. They […]
Suiting up with Al-Mg-Si: New protective coating for steel in ships and marine and coastal facilities
Phys.org January 5, 2022 Improving the corrosion resistance of steel by coating it with aluminum for marine applications is limited because of chloride ions in sea water on aluminum. Researchers in South Korea fabricated alloy films with excellent corrosion resistance by depositing an Mg film on Al-Si coated steel sheets and applying heat treatment. The fabricated Al-Mg-Si alloy film formed a corrosion product film composed of two layers, showing an excellent barrier effect against corrosion factors. The Mg in the film fabricated by heat treatment for 5 min was widely distributed in a dissolved state on the AI phase and […]
Study shows that zwitterions can raise the dielectric constant of soft materials
Phys.org December 17, 2021 To create efficient energy storage solutions and actuators, engineers need materials with high dielectric constant. The current method of incorporating polar additives with a high dielectric constant has not yielded high enough dielectric constant for many applications. Researchers at Penn State University have demonstrated a new method for raising the dielectric constant by adding zwitterions, small molecules with one positive electrical charge and one negative electrical charge separated by covalent bonds. Zwitterions are non-volatile molecules that are highly polar. In their recent experiments, the team added the zwitterions to polymeric single-ion conductors. Zwitterions raised dielectric constant […]
Magnetene: Graphene-like 2D material leverages quantum effects to achieve ultra-low friction
Phys.org November 17, 2021 Low-friction interfaces in 2D materials are often attributed to van der Waals (vdW) bonding of 2D materials, and nanoscale and quantum confinement effects can also act to modify the atomic interactions of a 2D material producing unique interfacial properties. An international team of researchers (Canada, USA – Rice University) has demonstrated low-friction behavior of magnetene, a non-vdW 2D material obtained via the exfoliation of magnetite, showing statistically similar friction to benchmark vdW 2D materials. They found that this low friction is due to 2D confinement effects of minimized potential energy surface corrugation, lowered valence states reducing […]
Molecular interfaces for innovative sensors and data storage devices
Nanowerk October 20, 2021 To better understand electronic and magnetic properties and understanding the mechanisms that govern the interactions at the interface an international team of researchers (Germany, Austria, Switzerland, Italy) coupled nickel-porphyrin with copper. Using theoretical and experimental spectro-microscopy approach they showed that the charge transfer occurring at the interface between nickel tetraphenyl porphyrins and copper changes both spin and oxidation states of the Ni ion. The chemically active Ni(I), even in a buried multilayer system, can be functionalized with nitrogen dioxide, allowing a selective tuning of the electronic properties of the Ni center that is switched to a […]
New type of magnetism unveiled in an iconic material
Phys.org October 5, 2021 Using low-energy muon spin spectroscopy an international team of researchers (Italy, Germany, UK, Israel, South Korea, Japan) discovered the existence of surface magnetism in Sr2RuO4 in its normal state. They detected static weak dipolar fields yet manifesting at an onset temperature higher than 50 K. They ascribed this unconventional magnetism to orbital loop currents forming at the reconstructed Sr2RuO4 surface. The results confirm that physical properties can be dramatically modified at a complex material surface and at interfaces within thin film heterostructures, and these modifications can be exploited for discovering new science for basic and applied research […]
Smuggling light through opaque materials
Nanowerk October 5, 2021 Chalcogenide glasses have long been constrained to the near- and mid-infrared with respect to their applications in photonics because they strongly absorb wavelengths of light in the visible and ultraviolet parts of electromagnetic spectrum. An international team of researchers (USA – Duke University, US Naval Research Laboratory, industry, university of Pennsylvania, Aviation and Missile Center, Aviation and Missile Center, US Army, Italy) has experimentally demonstrated and reported near-infrared to ultraviolet frequency conversion in an As2S3-based metasurface, enabled by a phase locking mechanism between the pump and the inhomogeneous portion of the third harmonic signal. Due to […]
Physicists make square droplets and liquid lattices
Nanowerk September 15, 2021 To study if the non-equilibrium structures can be controlled or be useful researchers in Finland subjected combinations of oils with different dielectric constants and conductivities to an electric field. When an electric field turned on over the mixture, electrical charge accumulated at the interface between the oils shearing the interface out of thermodynamic equilibrium. The liquids were confined into a thin, nearly two-dimensional sheet taking various droplets and patterns. The droplets could be made into squares and hexagons with straight sides. The two liquids could be also made to form into interconnected lattices, grid patterns that […]
Just by changing its shape, scientists show they can alter material properties
Nanowerk September 13, 2021 An international team of researchers (USA – Argonne National Laboratory, University of Chicago, Israel) explored confined transport using a patterned structure in titania films, with feature sizes of 11–20 nm. They described how confinement changes the competing charge transport mechanisms, the patterned antidot array leads to displacement fields and confines the charge density that results in modified and emergent electron transport with an increase in conductivity. This emergent behavior can be described by considering electron interference effects. Characterization of the charge transport with electron holography and impedance spectroscopy, and through comparison with modeling, showed that nanoscale […]