Power applications of superconductors will be tremendously boosted if an effective method for magnetic flux immobilization is discovered. Here, we report the most efficient vortex-pinning mechanism reported so far which, in addition, is based on a low-cost chemical solution deposition technique. A dense array of defects in the superconducting matrix is induced in YBa(2)Cu(3)O(7-x)-BaZrO(3) nanocomposites where BaZrO(3) nanodots are randomly oriented. Non-coherent interfaces are the driving force for generating a new type of nanostructured superconductor. Angle-dependent critical-current measurements demonstrate that a strong and isotropic flux-pinning mechanism is extremely effective at high temperatures and high magnetic fields leading to high-temperature superconductors with record values of pinning force. The maximum vortex-pinning force achieved at 65 K, 78 GN m(-3), is 500% higher than that of the best low-temperature NbTi superconductors at 4.2 K and so a great wealth of high-field applications will be possible at high temperatures.
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http://dx.doi.org/10.1038/nmat1893 | DOI Listing |
Soft Matter
January 2025
School of Chemistry and University of Sydney Nano Institute, The University of Sydney, Sydney, NSW, 2006, Australia.
Self-assembly of amphiphilic molecules can take place in extremely concentrated salt solutions, such as inorganic molten salt hydrates or hydrous melts. The intermolecular interactions governing the organization of amphiphilic molecules under such extreme conditions are not yet fully understood. In this study, we investigated the specific effects of ions on the self-assembly of the non-ionic surfactant CH(OCHCH)OH (CE) under extreme salt concentrations, using calcium nitrate tetrahydrate as a reference.
View Article and Find Full Text PDFAdv Mater
January 2025
Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Hubei Provincial Engineering Research Center of Emerging Functional Coating Materials, School of Resource and Environmental Sciences, Wuhan University, Wuhan, 430079, China.
Cellulose nanofibers (CNFs) are ideal building blocks for creating lightweight and strong bulk structural materials due to their unique supramolecular structure and exceptional mechanical properties within the crystalline regions. However, assembling CNFs into dense bulk structural materials with customizable shape and functionalities remains a great challenge, hindering their practical applications. Here, the dewatering issue of aqueous CNF dispersions is addressed by regulating supramolecular scale hydrophilicity using lactic acid, combined with hot-press molding.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
John A. Paulson School of Engineering and Applied Sciences and Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138.
Liquid crystal elastomers (LCEs) exhibit reversible shape morphing behavior when cycled above their nematic-to-isotropic transition temperature. During extrusion-based 3D printing, LCE inks are subjected to coupled shear and extensional flows that can be harnessed to spatially control the alignment of their nematic director along prescribed print paths. Here, we combine experiment and modeling to elucidate the effects of ink composition, nozzle geometry, and printing parameters on director alignment.
View Article and Find Full Text PDFSoft Matter
January 2025
Department of Physics and Soft Materials Research Center, University of Colorado, Boulder, CO 80309, USA.
The current intense study of ferroelectric nematic liquid crystals was initiated by the observation of the same ferroelectric nematic phase in two independently discovered organic, rod-shaped, mesogenic compounds, RM734 and DIO. We recently reported that the compound RM734 also exhibits a monotropic, low-temperature, apolar phase having reentrant isotropic symmetry (the I phase), the formation of which is facilitated to a remarkable degree by doping with small (below 1%) amounts of the ionic liquid BMIM-PF. Here we report similar phenomenology in DIO, showing that this reentrant isotropic behavior is not only a property of RM734 but is rather a more general, material-independent feature of ferroelectric nematic mesogens.
View Article and Find Full Text PDFSmall
January 2025
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China.
Improved birefringence, given its capacity to modulate polarized light, holds a lively role in the optoelectronic industry. Traditionally, alkaline-earth metal halides have possessed low birefringence due to their nearly optical isotropic properties. Herein, the substitution of interlayer anion with linear S─S unit that meticulously engineered by reduced valence state and strong covalent bond is integrated into the optically isotropic BaF, offering the new salt-inclusion chalcogenide BaFS.
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