TY - JOUR AU - Tóth, Boglárka AU - Farkas, Dániel Gergely AU - Amelin, K. AU - Rõõm, T. AU - Nagel, U. AU - Udvardi, László AU - Szunyogh, László AU - Rózsa, Levente AU - Ito, T. AU - Bordács, Sándor TI - Terahertz spin-wave excitations in the transverse conical phase of BiFeO3 JF - PHYSICAL REVIEW B J2 - PHYS REV B VL - 109 PY - 2024 IS - 14 PG - 10 SN - 2469-9950 DO - 10.1103/PhysRevB.109.144424 UR - https://m2.mtmt.hu/api/publication/34823661 ID - 34823661 LA - English DB - MTMT ER - TY - JOUR AU - Vadas, Dániel AU - Bordácsné Bocz, Katalin AU - Igricz, Tamás AU - Volk, János AU - Bordács, Sándor AU - Madarász, Lajos AU - Marosi, György TI - Novel manufacturing method for highly flexible poly(lactic acid) foams and ferroelectrets JF - ADVANCED INDUSTRIAL AND ENGINEERING POLYMER RESEARCH J2 - ADV INDUST ENGIN POLYMER RES VL - 7 PY - 2024 IS - 2 SP - 215 EP - 225 PG - 11 SN - 2542-5048 DO - 10.1016/j.aiepr.2023.03.005 UR - https://m2.mtmt.hu/api/publication/33836337 ID - 33836337 AB - Poly (lactic acid) (PLA) foams have demonstrated a high variety of functional characteristics, still, the rigidity of this cellular material remains a major limiting factor when it comes to implementation options. In this contribution, PLA foams with outstanding flexibility were created for the first time by a new approach of uniaxial stretching and immediate relaxation following supercritical CO2-assisted extrusion foaming. Instead of improving the resilience of the PLA raw material, structural elasticity of the foam was achieved via altering the deformation mechanism from cell wall collapse or rupture towards reversible and extensive flexural strain. In addition, PLA foams with excellent piezoelectric properties were also achieved via high-voltage corona poling, giving additional function to the lens-like anisotropic foam cells. This foaming technology creates the opportunity to produce PLA piezoelectrets in a way entirely different from the state-of-the-art methods. Correlation between the tensile as well as compression elongations and moduli, cell morphology and longitudinal piezoelectric coefficients (d33) of electretized foam samples were studied. Unprecedented reversible tensile elongations of up to 16% and total elongations of up to 35% were reached, as well as considerable d33 values in the range of 50–320 pC/N were obtained for PLA ferroelectrets. LA - English DB - MTMT ER - TY - JOUR AU - Tóth, Boglárka AU - Amelin, K. AU - Rõõm, T. AU - Nagel, U. AU - Bauernfeind, A. AU - Tsurkan, V. AU - Prodan, L. AU - Krug, von Nidda H.-A. AU - Scheffler, M. AU - Kézsmárki, I. AU - Bordács, Sándor TI - Broadband magnetic resonance spectroscopy in MnSc2S4 JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 13 PY - 2023 IS - 1 PG - 7 SN - 2045-2322 DO - 10.1038/s41598-023-37911-6 UR - https://m2.mtmt.hu/api/publication/34069706 ID - 34069706 N1 - Department of Physics, Institute of Physics, Budapest University of Technology and Economics, Műegyetem rkp. 3.Budapest H-1111, Hungary National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn, 12618, Estonia 1. Physikalisches Institut, University of Stuttgart, Pfaffenwaldring 57, Stuttgart, 70569, Germany Experimental Physics V, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, Augsburg, 86159, Germany Institute of Applied Physics, Moldova State University, Republic of Moldova, 5 Academiei Str., Chisinau, 2028, Moldova Department of Physics, Institute of Physics, Budapest University of Technology and Economics, Műegyetem rkp. 3.Budapest H-1111, Hungary ELKH-BME Condensed Matter Research Group, Budapest University of Technology and Economics, Műegyetem rkp. 3.Budapest H-1111, Hungary Export Date: 20 July 2023 WoS:hiba:001026178300022 2023-12-31 20:20 cím nem egyezik AB - Recent neutron scattering experiments suggested that frustrated magnetic interactions give rise to antiferromagnetic spiral and fractional skyrmion lattice phases in MnSc2S4. Here, to trace the signatures of these modulated phases, we studied the spin excitations of MnSc2S4 by THz spectroscopy at 300 mK and in magnetic fields up to 12 T and by broadband microwave spectroscopy at various temperatures up to 50 GHz. We found a single magnetic resonance with frequency linearly increasing in field. The small deviation of the Mn2+ ion g-factor from 2, g = 1.96, and the absence of other resonances imply very weak anisotropies and negligible contribution of higher harmonics to the spiral state. The significant difference between the dc magnetic susceptibility and the lowest frequency ac susceptibility in our experiment implies the existence of mode(s) outside of the measured frequency windows. The combination of THz and microwave experiments suggests a spin gap opening below the ordering temperature between 50 GHz and 100 GHz. LA - English DB - MTMT ER - TY - JOUR AU - Schilberth, F. AU - Jiang, M.-C. AU - Minami, S. AU - Kassem, M. A. AU - Mayr, F. AU - Koretsune, T. AU - Tabata, Y. AU - Waki, T. AU - Nakamura, H. AU - Guo, G.-Y. AU - Arita, R. AU - Kézsmárki, I. AU - Bordács, Sándor TI - Nodal-line resonance generating the giant anomalous Hall effect of Co 3 Sn 2 S 2 JF - PHYSICAL REVIEW B J2 - PHYS REV B VL - 107 PY - 2023 IS - 21 SN - 2469-9950 DO - 10.1103/PhysRevB.107.214441 UR - https://m2.mtmt.hu/api/publication/34039687 ID - 34039687 N1 - Experimentalphysik v, Center for Electronic Correlations and Magnetism, Institute for Physics, Augsburg University, Augsburg, D-86135, Germany Department of Physics, Institute of Physics, Budapest University of Technology and Economics, Muegyetem rkp. 3, Budapest, H-1111, Hungary Department of Physics, Center for Theoretical Physics, National Taiwan University, Taipei, 10617, Taiwan Riken Center for Emergent Matter Science, 2-1 Hirosawa, Wako, 351-0198, Japan Department of Mechanical Engineering and Science, Kyoto University, Nishikyo-ku, Kyoto, 615-8540, Japan Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan Department of Materials Science and Engineering, Kyoto University, Kyoto, 606-8501, Japan Department of Physics, Faculty of Science, Assiut University, Assiut, 71516, Egypt Department of Physics, Tohoku University, Sendai, 980-8578, Japan Physics Division, National Center for Theoretical Sciences, Taipei, 10617, Taiwan Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Meguro-ku, Tokyo, 153-8904, Japan ELKH-BME Condensed Matter Research Group, Budapest University of Technology and Economics, Muegyetem rkp. 3, Budapest, H-1111, Hungary Export Date: 20 July 2023 LA - English DB - MTMT ER - TY - JOUR AU - Dutta, Rajesh AU - Thoma, Henrik AU - Sazonov, Andrew AU - Náfrádi, Bálint AU - Meven, Martin AU - Gukasov, Arsen AU - Kocsis, Vilmos AU - Zeitler, Uli AU - Puri, Alessandro AU - Tokunaga, Yusuke AU - Taguchi, Yasujiro AU - Tokura, Yoshinori AU - Bordács, Sándor AU - Kézsmárki, István AU - Hutanu, Vladimir TI - Magnetic structure of the two-dimensional XY antiferromagnet Sr2CoSi2 O7 studied using single-crystal neutron diffraction JF - PHYSICAL REVIEW B J2 - PHYS REV B VL - 107 PY - 2023 IS - 1 SN - 2469-9950 DO - 10.1103/PhysRevB.107.014420 UR - https://m2.mtmt.hu/api/publication/33644692 ID - 33644692 N1 - Institut für Kristallographie, RWTH Aachen Universität, Aachen, 52066, Germany Jülich Centre for Neutron Science, Heinz Maier-Leibnitz Zentrum, Garching, 85747, Germany European Spallation Source ERIC, P.O. Box 176, Lund, SE-221 00, Sweden EPFL, Laboratory of Nanostructures and Novel Electronic Materials, Lausanne, 1015, Switzerland Laboratoire Léon Brillouin, CEA, CNRS, CE-Saclay, Gif-sur-Yvette, 91191, France RIKEN Center for Emergent Matter Science (CEMS), Saitama, Wako, 351-0198, Japan Institut für Festkörperforschung, Leibniz IFW Dresden, Dresden, 01069, Germany High Field Magnet Laboratory (HFML-EMFL), Radboud University, Toernooiveld 7, Nijmegen, 6525 ED, Netherlands CNR-IOM-OGG, C/o ESRF-The European Synchrotron, 71 Avenue des Martyrs, Grenoble, 38000, France Department of Advanced Materials Science, University of Tokyo, Kashiwa, 277-8561, Japan Quantum-Phase Electronics Center, Department of Applied Physics, University of Tokyo, Tokyo, 113-8656, Japan Department of Applied Physics, University of Tokyo, Hongo, Tokyo, 113-8656, Japan Department of Physics, Institute of Physics, Budapest University of Technology and Economics, Müegyetem rkp. 3, Budapest, H-1111, Hungary Department of Experimental Physics v, University of Augsburg, Augsburg, 86159, Germany Correspondence Address: Dutta, R.; Institut für Kristallographie, Germany; email: rajesh.dutta@frm2.tum.de Correspondence Address: Thoma, H.; Institut für Kristallographie, Germany; email: henrik.thoma@frm2.tum.de LA - English DB - MTMT ER - TY - JOUR AU - Kocsis, V. AU - Tokunaga, Y. AU - Rõõm, T. AU - Nagel, U. AU - Fujioka, J. AU - Taguchi, Y. AU - Tokura, Y. AU - Bordács, Sándor TI - Spin-Lattice and Magnetoelectric Couplings Enhanced by Orbital Degrees of Freedom in Polar Multiferroic Semiconductors JF - PHYSICAL REVIEW LETTERS J2 - PHYS REV LETT VL - 130 PY - 2023 IS - 3 SN - 0031-9007 DO - 10.1103/PhysRevLett.130.036801 UR - https://m2.mtmt.hu/api/publication/33644684 ID - 33644684 N1 - CODEN: PRLTA LA - English DB - MTMT ER - TY - JOUR AU - Basa, Péter AU - Fodor, B. AU - Nagy, Zs. AU - Oyunbolor, B. AU - Hajtman, A. AU - Bordács, Sándor AU - Kézsmárki, István AU - Halbritter, András Ernő AU - Orbánová, Agnesa TI - Analysis of malaria infection byproducts with Mueller matrix transmission ellipsometry JF - THIN SOLID FILMS J2 - THIN SOLID FILMS VL - 766 PY - 2023 SN - 0040-6090 DO - 10.1016/j.tsf.2022.139637 UR - https://m2.mtmt.hu/api/publication/33548398 ID - 33548398 AB - In this work, hemozoin, a microcrystalline byproduct of the malaria parasites was studied by transmission Mueller matrix ellipsometry. Measurement data was collected for different magnetic field orientations and as a function of the density of the hemozoin suspension. Our ellipsometric study demonstrates the magnetic alignment of the hemozoin crystals via the corresponding large linear birefringence and dichroism signals. These results reveal optical anisotropies of this material, which could be utilized for future optimization of detection schemes or optical instruments for diagnostic use. LA - English DB - MTMT ER - TY - JOUR AU - Peedu, L. AU - Kocsis, V. AU - Szaller, Dávid AU - Forrai, B. AU - Bordács, Sándor AU - Kézsmárki, István AU - Viirok, J. AU - Nagel, U. AU - Bernáth, B. AU - Kamenskyi, D.L. AU - Miyata, A. AU - Portugall, O. AU - Tokunaga, Y. AU - Tokura, Y. AU - Taguchi, Y. AU - Rõõm, T. TI - Terahertz spectroscopy of spin excitations in magnetoelectric LiFePO4 in high magnetic fields JF - PHYSICAL REVIEW B J2 - PHYS REV B VL - 106 PY - 2022 IS - 13 SN - 2469-9950 DO - 10.1103/PhysRevB.106.134413 UR - https://m2.mtmt.hu/api/publication/33189817 ID - 33189817 N1 - L.P., V.K., and D.S. contributed equally to this work. LA - English DB - MTMT ER - TY - JOUR AU - F., Schilberth AU - N., Unglert AU - L., Prodan AU - F., Meggle AU - J., Ebad Allah AU - C. A., Kuntscher AU - A. A., Tsirlin AU - V., Tsurkan AU - J., Deisenhofer AU - L., Chioncel AU - I., Kézsmárki AU - Bordács, Sándor TI - Magneto-optical detection of topological contributions to the anomalous Hall effect in a kagome ferromagnet JF - PHYSICAL REVIEW B J2 - PHYS REV B VL - 106 PY - 2022 IS - 14 SN - 2469-9950 DO - 10.1103/PhysRevB.106.144404 UR - https://m2.mtmt.hu/api/publication/33106237 ID - 33106237 N1 - Experimentalphysik v, Center for Electronic Correlations and Magnetism, Institute for Physics, Augsburg University, Augsburg, D-86135, Germany Department of Physics, Institute of Physics, Budapest University of Technology and Economics, Muegyetem rakpart 3., Budapest, H-1111, Hungary Theoretische Physik III, Center for Electronic Correlations and Magnetism, Institute for Physics, Augsburg University, Augsburg, D-86135, Germany Experimentalphysik II, Institute for Physics, Augsburg University, Augsburg, D-86135, Germany Experimentalphysik VI, Center for Electronic Correlations and Magnetism, Institute for Physics, Augsburg University, Augsburg, D-86135, Germany Institute of Applied Physics, Chişinǎu, MD-2028, Moldova Export Date: 25 October 2022 AB - A single ferromagnetic kagome layer is predicted to realize a Chern insulator with quantized Hall conductance, which upon stacking can become a Weyl semimetal with a large anomalous Hall effect (AHE) and magnetooptical activity. Indeed, in the kagome bilayer material Fe3Sn2, a large AHE was detected. In order to directly probe the responsible band structure features, we measure the optical Hall conductivity spectra in addition to the diagonal optical conductivity over a broad frequency range. Since the former is the energy selective measure of the intrinsic contributions to the AHE, we identify their common origin with the help of momentum- and banddecomposed optical conductivity spectra obtained from first principles calculations. We find that low-energy transitions, tracing "helical volumes" in momentum space reminiscent of the formerly predicted helical nodal lines, substantially contribute to the AHE, which is further increased by contributions from multiple higherenergy interband transitions. Our study also reveals that in this kagome magnet, local Coulomb interactions lead to remarkable band reconstructions near the Fermi level. LA - English DB - MTMT ER - TY - JOUR AU - Butykai, Ádám AU - Geirhos, K. AU - Szaller, Dávid AU - Kiss, László Ferenc AU - Balogh, L. AU - Azhar, M. AU - Garst, M. AU - DeBeer-Schmitt, L. AU - Waki, T. AU - Tabata, Y. AU - Nakamura, H. AU - Kézsmárki, I. AU - Bordács, Sándor TI - Squeezing the periodicity of Néel-type magnetic modulations by enhanced Dzyaloshinskii-Moriya interaction of 4d electrons JF - NPJ QUANTUM MATERIALS J2 - NPJ QUANTUM MATER VL - 7 PY - 2022 IS - 1 PG - 7 SN - 2397-4648 DO - 10.1038/s41535-022-00432-y UR - https://m2.mtmt.hu/api/publication/32775065 ID - 32775065 AB - In polar magnets, such as GaV4S8, GaV4Se8 and VOSe2O5, modulated magnetic phases namely the cycloidal and the Néel-type skyrmion lattice states were identified over extended temperature ranges, even down to zero Kelvin. Our combined small-angle neutron scattering and magnetization study shows the robustness of the Néel-type magnetic modulations also against magnetic fields up to 2 T in the polar GaMo4S8. In addition to the large upper critical field, enhanced spin-orbit coupling stabilize cycloidal, Néel skyrmion lattice phases with sub-10 nm periodicity and a peculiar distribution of the magnetic modulation vectors. Moreover, we detected an additional single-q state not observed in any other polar magnets. Thus, our work demonstrates that non-centrosymmetric magnets with 4d and 5d electron systems may give rise to various highly compressed modulated states. LA - English DB - MTMT ER -