Phys.org November 29, 2022 DNA conformation is well understood for biological processes. An international team of researchers (Austria, Poland, Italy) focused on chains interlocking the rings and observed their behavior and how they could be used to design innovative materials. They showed that circular polycatenanes have physical and geometrical properties very similar to those of double stranded DNA rings. They demonstrated that the connection of local and global properties holds for these structures too, that is there is a connection between what occurs in a part of the structure and in its whole. The amount of twist of the polycatenanes […]
Tag Archives: Materials science
Leading the way in superconductor research: New compounds of lanthanum and hydrogen
Phys.org November 22, 2022 An international team of researchers (Germany, UK, Sweden, USA – University of Chicago) has presented the results of their single-crystal X-ray diffraction studies on lanthanum hydrides which revealed an unexpected chemical and structural diversity of lanthanum hydrides synthesized in the range of 50 to 180 GPa. They produced seven lanthanum hydrides LaH3, LaH~4, LaH4+δ, La4H23, LaH6+δ, LaH9+δ, and LaH10+δ, and determined the atomic coordinates of lanthanum in their structures. The regularities in rare-earth element hydrides the team has shown provide clues to guide the search for other synthesizable hydrides and candidate high-temperature superconductors. The hydrogen content variability […]
Scientists synthesize an analog of the Earth’s most complex mineral in a laboratory
Phys.org November 21, 2022 Through the combination of low-temperature hydrothermal synthesis and room-temperature evaporation an international team of researchers (Russia, Czech Republic, USA – University of Notre Dame) has synthesized a mineral similar in composition and crystal structure to the Earth’s most complex mineral, ewingite. The crystal structures of both natural and synthetic compounds were based on supertetrahedral uranyl-carbonate nanoclusters that are arranged according to the cubic body-centered lattice principle. The structure and composition of the uranyl carbonate nanocluster were refined using the data on synthetic material. Although the stability of natural ewingite is higher (according to visual observation and […]
Electrons zip along quantum highways in new material
Nanowerk November 9, 2022 An international team of researchers (USA – University of Chicago, Pennsylvania State University, Israel) discovered a new material, MnBi6Te10, which could be used to create quantum highways useful in connecting the internal components of energy-efficient quantum computers. In the ferromagnetic phase, an energy gap of 15 meV was resolved at the Dirac point on the MnBi2Te4 termination. In contrast, antiferromagnetic MnBi6Te10 exhibited gapless topological surface states on all terminations. Measurements revealed substantial Mn vacancies and Mn migration in ferromagnetic MnBi6Te10. They provided a conceptual framework where a cooperative interplay of these defects drove a delicate change […]
Next generation material that adapts to its history
Nanowerk November 15, 2022 The responses of living systems dynamically adapt based on the repetition, intensity, and history of stimuli. Such plasticity is ubiquitous in biology, which is profoundly linked to memory and learning. Inspired by living systems, researchers in Finland synthesised micrometre-sized magnetic beads which were then stimulated by a magnetic field. When the magnet was on, the beads stacked up to form pillars. The strength of the magnetic field affects the shape of the pillars, which in turn affects how well they conduct electricity. When they exposed the beads to a quickly pulsing magnetic field, the material became […]
One-unit-cell thick semiconductors with room-temperature magnetism
Nanowerk November 15, 2022 Researchers in China have developed a confined-van der Waals epitaxial approach to synthesizing air-stable semiconducting cobalt ferrite nanosheets with thickness down to one unit cell using a facile chemical vapor deposition process. They demonstrated hard magnetic behavior and magnetic domain evolution by means of vibrating sample magnetometry, magnetic force microscopy and magneto-optical Kerr effect measurements, which showed high Curie temperature above 390 K and strong dimensionality effect. According to the researchers their work provides possibilities for numerous novel applications in computing, sensing and information storage…read more. Open Access TECHNICAL ARTICLE
Team creates crystals that generate electricity from heat
Phys.org November 6, 2022 An international team of researchers (France, Japan, Germany) synthesized a series of self-doped compounds Cu2+xMn1−xGeS4 through Cu for Mn substitution. Using a combination of powder X-ray diffraction, high resolution transmission electron microscopy and precession-assisted electron diffraction tomography, they showed that the materials were composed of interconnected enargite- and stannite-type structures, via the formation of nanodomains with a high density of coherent interfaces. By combining experiments with ab initio electron and phonon calculations, they discussed the structure–thermoelectric properties relationships and clarified the interesting crystal chemistry in this system. They demonstrated that excess Cu+ substituted for Mn2+ dopes […]
Electrical gating of the charge-density-wave quantum phases opens innovative electronic applications
Nanowerk November 1, 2022 Recent years witnessed a rebirth of the field of CDW materials and devices, partially driven by an interest in layered quasi-2D van der Waals materials where CDW phases can manifest themselves at room temperature. Despite numerous attempts, the electrical gating of the CDW phase, which is needed for many practical applications, remained elusive. An international team of researchers (USA – UC Riverside, University of Georgia, Poland) has demonstrated the electrical gating of the charge-density-wave phases and current in h-BN-capped three-terminal 1T-TaS2 heterostructure devices. The evolution of the hysteresis and the presence of abrupt spikes in the […]
In nanotube science, is boron nitride the new carbon?
Nanowerk October 31, 2022 Boron nitride nanotubes (BNNTs) possess a broad range of applications because of several engineering-relevant properties, including high specific strength and stiffness, thermal stability, and transparency to visible light. The morphology of the nanoscale fibers must be controlled to maximize such properties, which can be achieved by synthesizing long aligned arrays of crystalline hexagonal boron nitride (hBN) nanotubes. An international team of researchers (USA – MIT, Japan) synthesized high-quality millimeter length, vertically aligned (VA-) BNNTs using free-standing carbon nanotube (CNT) arrays as scaffolds. In addition to high optical transparency of the VA-BNNTs, they also demonstrated several micro- […]
Scientists discover material that can be made like a plastic but conducts like metal
Science Daily October 26, 2022 An international team of researchers (USA – University of Chicago, Stony Brook University, Argonne National Laboratory, South Korea) discovered a way to create a material that can be made like a plastic but conducts electricity more like a metal when they strung nickel atoms like pearls into a string of molecular beads made of carbon and sulfur. The material easily and strongly conducted electricity when heated or chilled or exposed to air and humidity, or even dripped acid and base. But the most striking thing was that the molecular structure of the material was disordered. […]