Sep 13, 2024
Imaging Antiferromagnetic Domains
Posted by Saúl Morales Rodriguéz in category: materials
A simple light microscopy setup can map the micrometer-scale domains of a potentially useful class of magnetic materials.
A simple light microscopy setup can map the micrometer-scale domains of a potentially useful class of magnetic materials.
Ultraviolet photons induce potassium niobate to behave like a potent solid-state refrigerant, according to new calculations.
Claudio Cazorla of the Polytechnic University of Catalonia in Spain and his collaborators have used a suite of numerical methods to discover that the archetypal ferroelectric material, potassium niobate (KNO), also exhibits a photocaloric effect: In response to ultraviolet light, KNO reversibly absorbs heat [1]. Because the effect is large and works at a wide range of temperatures, including room temperature, KNO could serve as the working medium for new cooling devices.
KNO owes its ferroelectric and photocaloric effects to its perovskite crystal structure, which features a niobium ion surrounded by an octahedral cage of oxygen ions. At low temperatures, the niobium ion is offset from the cage’s center, which induces an electric polarization (the ferroelectric effect). Above 700 K, KNO adopts a nonpolar configuration as its most stable phase.
Several fields of mathematics have developed in total isolation, using their own “undecipherable” coded languages. In a new study published in Proceedings of the National Academy of Sciences, Tamás Hausel, professor of mathematics at the Institute of Science and Technology Austria (ISTA), presents “big algebras,” a two-way mathematical ‘dictionary’ between symmetry, algebra, and geometry, that could strengthen the connection between the distant worlds of quantum physics and number theory.
A nationwide analysis of community-level floodplain development found that over two-million acres of floodplain were developed over the past two decades across the United States, with roughly half of all new floodplain housing built in Florida.
The interactions between quantum spins underlie some of the universe’s most interesting phenomena, such as superconductors and magnets. However, physicists have difficulty engineering controllable systems in the lab that replicate these interactions.
A small black hole must work harder against gravity to keep from collapsing. In rapidly rotating black holes, the Ni shell would collapse to a torus, as possibly reflected in the dramatic photos of supermassive black holes.
At a deeper level, the gravity/Λ mechanism might be seen as a kind of quantum overlay of the Ni solutions, a possible step towards reconciliation of the quantum gravity and general relativity perspectives.
Cosmologists will not be quick to endorse a shell universe. There is still much heavy lifting still to do, for instance, in matching the Ni solutions to the observed universe. Dark matter and dark energy will not lightly be cast aside. But if I am right, the universe is not as you may always have thought.
Researchers from Monash University, part of the FLEET Center, have revealed a generic approach towards intrinsic magnetic second-order topological insulators. These materials are crucial for advancements in spintronics, an emerging field aiming at using spin degree of freedom to deliver information. Their study is published in Nano Letters.
A new software package developed by researchers at Macquarie University can accurately model the way waves—sound, water or light—are scattered when they meet complex configurations of particles.
New Linux malware ‘Hadooken’ targets Oracle Weblogic, deploys crypto miners and DDoS botnet. Exploits vulnerabilities for lateral movement.
New Android malware ‘Ajina. Banker’ targets bank customers in Central Asia, stealing financial data and intercepting 2FA messages via Telegram channels.