The interplay between a topological electronic structure and magnetism may result in intricate physics. In this work, we describe a case of rather peculiar coexistence or competition of several magnetic phases below seemingly single antiferromagnetic transition in LnSbTe (Ln = Ho and Tb) topological semimetals, the magnetic members of the ZrSiS/PbFCl structure type (space group P4/nmm). Neutron diffraction experiments reveal a complex multi-step order below TN = 3.8 K (Ln = Ho) and TN = 6.4 K (Ln = Tb). Magnetic phases can be described using four propagation vectors k1 = (1/2 0 0) and k2 = (1/2 0 1/4) at a base temperature of 1.7 K, which transform into incommensurate vectors k1′ = (1/2 – δ 0 0) and k3 = (1/2 – δ 0 1/2) at elevated temperatures in both compounds. Together with the refined models of magnetic structures, we present the group theoretical analysis of magnetic symmetry of the proposed solutions. These results prompt further investigations of the relation between the electronic structure of those semimetals and the determined antiferromagnetic ordering existing therein.
High performance doped Li-rich Li1+xMn2-xO4 cathodes nanoparticles synthesized by facile, fast and efficient microwave-assisted hydrothermal route
Li-rich nanoparticles of Li1+xMn2-xO4 doped with Al, Co or Ni are successfully synthesized using a facile, fast and efficient microwave-assisted hydrothermal route. In this study, we demonstrate that nanocrystallinity and cationic doping play an important role in improving the electrochemical performance with respect to LiMn2O4 microparticles. They significantly reduce the charge-transfer resistance, lower the 1st cycle irreversible capacity to 6%, and achieve a capacity retention between 85 and 90% after 380 cycles, with excellent columbic efficiency close to 99%.
Methanol made from CO2 in the air can be transformed into carbon neutral fuels. New mechanistic understanding aids development of this sustainable alternative.
This work aimed to produce intermetallic samples of platinoid metals (active metal matrix) and lanthanides (co-metal) and via the method of Coupled Reduction, i.e. a thermal treatment of the combination of the lanthanide oxide and noble metal at high temperature, as high as 1100 °C, under a constant flow of H2. We have demonstrated by means of several techniques, such as Scanning Electron Microscope, Energy Dispersive X-Ray Spectroscopy, Alpha Spectrometry and Radiographic Imaging, that this method, at defined experimental conditions (temperature, pressure and concentration) yields a metallic lanthanide thin film when using platinum as active metal matrix. Conversely, the formation of a bulk intermetallic compound was obtained when using Pd as matrix. Those systems will have applications in different nuclear physic and radiochemistry studies, such as irradiation targets for production of superheavy elements and for nuclear data determination.
Chiara Favaretto, PhD student in the “Radionuclide Development” group at the Center for Radiopharmaceutical Sciences, received the NMB/Eckelman Young Investigator Award for the abstract entitled: “Production and radiochemical separation of terbium-155 from enriched gadolinium target material and its preliminary application in SPECT imaging”, presented at the International Symposium on Radiopharmaceutical Sciences (iSRS 2022).
Lithium-rich layered oxides, containing cobalt, despite being promising high-capacity cathode materials, need alternatives to eliminate toxic and geopolitically restricted cobalt. An ongoing search for low-cost, Co-free Li-rich cathode materials with a better structural stability lead to investigation of Li1.16Ni0.19Fe0.18Mn0.46O2 (LNFM), where cobalt is replaced by abundant iron. Our LNFM not only delivered a high capacity of 229 mAh/g but also has a stable average discharge voltage when cycled to upper cutoff potential of 4.8 V in additive-free electrolyte.
The CLOUD experiment reveals a new mechanism by which atmospheric particles form. The particles rapidly travel the world, globally impacting cloud formation and climate.
Targeted manipulations of an atom's magnetic moment are tricky, as the charge currents used for this process are extremely difficult to control . Now, a consortium of collaborators in Germany, Switzerland, Slovenia and Italy reports on a solution to this problem in the cover page article of Physic Review Letters 128, Vol. 15. As it appears, the magnetization of an atomic gas can be altered by high-power lasers using a patterned wave front. The method is promising for studying and manipulating the magnetic properties of matter at the nanoscale.
In the cuprates, high-temperature superconductivity, spin-density-wave order, and charge-density-wave (CDW) order are intertwined, and symmetry determination is challenging due to domain formation. We investigated the CDW in the prototypical cuprate La1.88Sr0.12CuO4 via x-ray diffraction employing uniaxial pressure as a domain-selective stimulus to establish the unidirectional nature of the CDW unambiguously.
Electronic nematicity, thought to be an ingredient in high temperature superconductivity, is primarily spin driven in FeSe finds a study in Nature Physics.