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Metal-organic framework compounds (MOFs) consist of inorganic and organic groups and are characterised by a large number of pores into which other molecules can be incorporated. MOFs are therefore interesting for many applications, for example for the storage of gases, but also for substance separation, sensor technology or catalysis. Some of these MOF structures react to different guest molecules by changing their structures. They are thus considered switchable.
One of these is DUT-8 , a material that has now been studied at the MX beamlines of BESSY II. MOF crystals can be analysed very well at the MX beamlines, says HZB expert Dr. Manfred Weiss, who heads the MX team. MOF crystals have many things in common with protein crystals. For example, both are interspersed with large pores, which are filled with liquid in the protein crystals, while those in MOFs provide space for guest molecules, Weiss explains.
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Credit: XU Yingsheng
Recently, the researchers from Institute of Solid State Physics, Hefei Institutes of Physical Science (HFIPS) of the Chinese Academy of Sciences, by using valence engineering, developed three manganese oxides as electrodes with different Mn valences for high-performance capacitive desalination.
Reverse osmosis and thermal distillation are widely used to treat salt water with high salt concentration, but they have disadvantages including high energy consumption and high cost.
As an alternative method, capacitive deionization (CDI) technology can remove charged ions from desalt water through electrosorption or pseudocapacitive reaction. However, there are few reports on manganese oxides with lower valence of Mn, compared with the number of reports on MnO2. Hence, whether there is a difference in desalination performance in such different valence states of Mn and the internal reasons are worth exploring.
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IMAGE: The illustration shows electrons in a topological quantum metal waiting to be activated by a magnetic field. Once they start moving, they follow a spiraling helix upwards - in contrast. view more
Credit: Copyright: Jörg Bandmann
This new 3D effect can be the foundation for topological quantum phenomena, which are believed to be particularly robust and therefore promising candidates for extremely powerful quantum technologies. These results have just been published in the scientific journal
Nature Communications.
Dr. Tobias Meng and Dr. Johannes Gooth are early career researchers in the Würzburg-Dresdner Cluster of Excellence ct.qmat that researches topological quantum materials since 2019. They could hardly believe the findings of a recent publication in Nature claiming that electrons in the topological metal zirconium pentatelluride (ZrTe5) move only in two-dimensional planes, despite the fact that the material is three-dimensional. Meng and G
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IMAGE: An example of a scheme of virtual excitations corresponding to the coupling of spins of chromium and iron ions with an electric field. The iron ion, due to the interaction. view more
Credit: Kazan Federal University
The authors, Kirill Vasin and Mikhail Eremin, contribute to the theory of electronic and structural properties of FeCr2O4 ferrimagnet. Due to the specific quantum state and the symmetry of FeO4 fragment, it has unusual electric and magnetic properties. Below TOO~150K, it lowers the symmetry with the macroscopic deformations due to the cooperative Jahn-Teller effect. The coupling between macroscopic deformation of the crystal FeCr2O4 and its inner ions shifts was revealed. The team enhanced the microscopic crystal field theory for 3D electrons with Kleiner s correction - the effect of penetrating charges density. It allows to have better prediction of electron-deformation coupling parameters, which is important for magnetostriction application