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- ItemSingle Molecule Magnetism with Strong Magnetic Anisotropy and Enhanced Dy∙∙∙Dy Coupling in Three Isomers of Dy-Oxide Clusterfullerene Dy2O@C82(Chichester : John Wiley and Sons Ltd, 2019) Yang, W.; Velkos, G.; Liu, F.; Sudarkova, S.M.; Wang, Y.; Zhuang, J.; Zhang, H.; Li, X.; Zhang, X.; Büchner, B.; Avdoshenko, S.M.; Popov, A.A.; Chen, N.A new class of single-molecule magnets (SMMs) based on Dy-oxide clusterfullerenes is synthesized. Three isomers of Dy2O@C82 with Cs(6), C3v(8), and C2v(9) cage symmetries are characterized by single-crystal X-ray diffraction, which shows that the endohedral Dy−(µ2-O)−Dy cluster has bent shape with very short Dy−O bonds. Dy2O@C82 isomers show SMM behavior with broad magnetic hysteresis, but the temperature and magnetization relaxation depend strongly on the fullerene cage. The short Dy−O distances and the large negative charge of the oxide ion in Dy2O@C82 result in the very strong magnetic anisotropy of Dy ions. Their magnetic moments are aligned along the Dy−O bonds and are antiferromagnetically (AFM) coupled. At low temperatures, relaxation of magnetization in Dy2O@C82 proceeds via the ferromagnetically (FM)-coupled excited state, giving Arrhenius behavior with the effective barriers equal to the AFM-FM energy difference. The AFM-FM energy differences of 5.4–12.9 cm−1 in Dy2O@C82 are considerably larger than in SMMs with {Dy2O2} bridges, and the Dy∙∙∙Dy exchange coupling in Dy2O@C82 is the strongest among all dinuclear Dy SMMs with diamagnetic bridges. Dy-oxide clusterfullerenes provide a playground for the further tuning of molecular magnetism via variation of the size and shape of the fullerene cage.
- ItemEuPRAXIA Conceptual Design Report(Berlin ; Heidelberg : Springer, 2020) Assmann, R. W.; Weikum, M. K.; Akhter, T.; Alesini, D.; Alexandrova, A. S.; Anania, M. P.; Andreev, N. E.; Andriyash, I.; Artioli, M.; Aschikhin, A.; Audet, T.; Jafarinia, F. J.; Jakobsson, O.; Jaroszynski, D. A.; Jaster-Merz, S.; Joshi, C.; Kaluza, M.; Kando, M.; Karger, O. S.; Karsch, S.; Khazanov, E.; Bacci, A.; Khikhlukha, D.; Kirchen, M.; Kirwan, G.; Kitégi, C.; Knetsch, A.; Kocon, D.; Koester, P.; Kononenko, O. S.; Korn, G.; Kostyukov, I.; Barna, I. F.; Kruchinin, K. O.; Labate, L.; Le Blanc, C.; Lechner, C.; Lee, P.; Leemans, W.; Lehrach, A.; Li, X.; Li, Y.; Libov, V.; Bartocci, S.; Lifschitz, A.; Lindstrøm, C. A.; Litvinenko, V.; Lu, W.; Lundh, O.; Maier, A. R.; Malka, V.; Manahan, G. G.; Mangles, S. P. D.; Marcelli, A.; Bayramian, A.; Marchetti, B.; Marcouillé, O.; Marocchino, A.; Marteau, F.; Martinez de la Ossa, A.; Martins, J. L.; Mason, P. D.; Massimo, F.; Mathieu, F.; Maynard, G.; Beaton, A.; Mazzotta, Z.; Mironov, S.; Molodozhentsev, A. Y.; Morante, S.; Mosnier, A.; Mostacci, A.; Müller, A. -S.; Murphy, C. D.; Najmudin, Z.; Nghiem, P. A. P.; Beck, A.; Nguyen, F.; Niknejadi, P.; Nutter, A.; Osterhoff, J.; Oumbarek Espinos, D.; Paillard, J. -L.; Papadopoulos, D. N.; Patrizi, B.; Pattathil, R.; Pellegrino, L.; Bellaveglia, M.; Petralia, A.; Petrillo, V.; Piersanti, L.; Pocsai, M. A.; Poder, K.; Pompili, R.; Pribyl, L.; Pugacheva, D.; Reagan, B. A.; Resta-Lopez, J.; Beluze, A.; Ricci, R.; Romeo, S.; Rossetti Conti, M.; Rossi, A. R.; Rossmanith, R.; Rotundo, U.; Roussel, E.; Sabbatini, L.; Santangelo, P.; Sarri, G.; Bernhard, A.; Schaper, L.; Scherkl, P.; Schramm, U.; Schroeder, C. B.; Scifo, J.; Serafini, L.; Sharma, G.; Sheng, Z. M.; Shpakov, V.; Siders, C. W.; Biagioni, A.; Silva, L. O.; Silva, T.; Simon, C.; Simon-Boisson, C.; Sinha, U.; Sistrunk, E.; Specka, A.; Spinka, T. M.; Stecchi, A.; Stella, A.; Bielawski, S.; Stellato, F.; Streeter, M. J. V.; Sutherland, A.; Svystun, E. N.; Symes, D.; Szwaj, C.; Tauscher, G. E.; Terzani, D.; Toci, G.; Tomassini, P.; Bisesto, F. G.; Torres, R.; Ullmann, D.; Vaccarezza, C.; Valléau, M.; Vannini, M.; Vannozzi, A.; Vescovi, S.; Vieira, J. M.; Villa, F.; Wahlström, C. -G.; Bonatto, A.; Walczak, R.; Walker, P. A.; Wang, K.; Welsch, A.; Welsch, C. P.; Weng, S. M.; Wiggins, S. M.; Wolfenden, J.; Xia, G.; Yabashi, M.; Boulton, L.; Zhang, H.; Zhao, Y.; Zhu, J.; Zigler, A.; Brandi, F.; Brinkmann, R.; Briquez, F.; Brottier, F.; Bründermann, E.; Büscher, M.; Buonomo, B.; Bussmann, M. H.; Bussolino, G.; Campana, P.; Cantarella, S.; Cassou, K.; Chancé, A.; Chen, M.; Chiadroni, E.; Cianchi, A.; Cioeta, F.; Clarke, J. A.; Cole, J. M.; Costa, G.; Couprie, M. -E.; Cowley, J.; Croia, M.; Cros, B.; Crump, P. A.; D’Arcy, R.; Dattoli, G.; Del Dotto, A.; Delerue, N.; Del Franco, M.; Delinikolas, P.; De Nicola, S.; Dias, J. M.; Di Giovenale, D.; Diomede, M.; Di Pasquale, E.; Di Pirro, G.; Di Raddo, G.; Dorda, U.; Erlandson, A. C.; Ertel, K.; Esposito, A.; Falcoz, F.; Falone, A.; Fedele, R.; Ferran Pousa, A.; Ferrario, M.; Filippi, F.; Fils, J.; Fiore, G.; Fiorito, R.; Fonseca, R. A.; Franzini, G.; Galimberti, M.; Gallo, A.; Galvin, T. C.; Ghaith, A.; Ghigo, A.; Giove, D.; Giribono, A.; Gizzi, L. A.; Grüner, F. J.; Habib, A. F.; Haefner, C.; Heinemann, T.; Helm, A.; Hidding, B.; Holzer, B. J.; Hooker, S. M.; Hosokai, T.; Hübner, M.; Ibison, M.; Incremona, S.; Irman, A.; Iungo, F.This report presents the conceptual design of a new European research infrastructure EuPRAXIA. The concept has been established over the last four years in a unique collaboration of 41 laboratories within a Horizon 2020 design study funded by the European Union. EuPRAXIA is the first European project that develops a dedicated particle accelerator research infrastructure based on novel plasma acceleration concepts and laser technology. It focuses on the development of electron accelerators and underlying technologies, their user communities, and the exploitation of existing accelerator infrastructures in Europe. EuPRAXIA has involved, amongst others, the international laser community and industry to build links and bridges with accelerator science — through realising synergies, identifying disruptive ideas, innovating, and fostering knowledge exchange. The Eu-PRAXIA project aims at the construction of an innovative electron accelerator using laser- and electron-beam-driven plasma wakefield acceleration that offers a significant reduction in size and possible savings in cost over current state-of-the-art radiofrequency-based accelerators. The foreseen electron energy range of one to five gigaelectronvolts (GeV) and its performance goals will enable versatile applications in various domains, e.g. as a compact free-electron laser (FEL), compact sources for medical imaging and positron generation, table-top test beams for particle detectors, as well as deeply penetrating X-ray and gamma-ray sources for material testing. EuPRAXIA is designed to be the required stepping stone to possible future plasma-based facilities, such as linear colliders at the high-energy physics (HEP) energy frontier. Consistent with a high-confidence approach, the project includes measures to retire risk by establishing scaled technology demonstrators. This report includes preliminary models for project implementation, cost and schedule that would allow operation of the full Eu-PRAXIA facility within 8—10 years.
- ItemAmorphous martensite in β-Ti alloys(London : Nature Publishing Group, 2018) Zhang, L.; Zhang, H.; Ren, X.; Eckert, J.; Wang, Y.; Zhu, Z.; Gemming, T.; Pauly, S.Martensitic transformations originate from a rigidity instability, which causes a crystal to change its lattice in a displacive manner. Here, we report that the martensitic transformation on cooling in Ti-Zr-Cu-Fe alloys yields an amorphous phase instead. Metastable β-Ti partially transforms into an intragranular amorphous phase due to local lattice shear and distortion. The lenticular amorphous plates, which very much resemble α′/α″ martensite in conventional Ti alloys, have a well-defined orientation relationship with the surrounding β-Ti crystal. The present solid-state amorphization process is reversible, largely cooling rate independent and constitutes a rare case of congruent inverse melting. The observed combination of elastic softening and local lattice shear, thus, is the unifying mechanism underlying both martensitic transformations and catastrophic (inverse) melting. Not only do we reveal an alternative mechanism for solid-state amorphization but also establish an explicit experimental link between martensitic transformations and catastrophic melting.
- ItemOptical orbital angular momentum conservation during the transfer process from plasmonic vortex lens to light(London : Nature Publishing Group, 2013) Yu, H.; Zhang, H.; Wang, Y.; Han, S.; Yang, H.; Xu, X.; Wang, Z.; Petrov, V.; Wang, J.We demonstrate the optical orbital angular momentum conservation during the transfer process from subwavelength plasmonic vortex lens (PVLs) to light and the generating process of surface plasmon polaritons (SPPs). Illuminating plasmonic vortex lenses with beams carrying optical orbital angular momentum, the SP vortices with orbital angular momentum were generated and inherit the optical angular momentum of light beams and PVLs. The angular momentum of twisting SP electromagnetic field is tunable by the twisted metal/dielectric interfaces of PVLs and angular momentum of illuminating singular light. This work may open the door for several possible applications of SP vortices in subwavelength region.