Freitag 22.09.2023 | |
IMW-Seminar | 09:00 |
Ort | IFW Dresden D2E.27 |
Referent | J. Ping Liu |
Thema | Magnetic Hardening in Low Dimensional Ferromagnets
How “hard” (coercive) a ferromagnet can be has been a puzzle for a century. Seven decades ago, William Fuller Brown offered his famous theorem to correlate coercivity with the magnetocrystalline anisotropy fields in ferromagnetic materials. However, the experimental coercivity values have been far below the calculated levels given by the theorem, which is called Brown’s Coercivity Paradox. Researchers have attempted to solve the paradox with sustained efforts; however, the paradox remains unsolved, and coercivity still cannot be predicted and calculated quantitatively by modeling. Progress has been made in the past 20 years in understanding coercivity mechanisms in nanoscale low-dimensional ferromagnets. In fact, ferromagnetism is a size-dependent physical phenomenon, as revealed by theoretical studies. However, nanoscale ferromagnetic samples with controllable size and shape have been available only in recent times. By adopting newly developed salt-matrix annealing, surfactant-assisted milling, and improved hydrothermal and chemical solution techniques, we used a bottom-up approach to produce nanostructured magnets and have successfully synthesized monodisperse ferromagnetic Fe-Pt, Fe-Co and Sm-Co nanoparticles and Co nanowires with extraordinary properties, which are strongly size- and shape-dependent. A study on size-dependent Curie temperature of the L10 ferromagnetic nanoparticles with sizes down to 2 nm has experimentally proved a finite-size effect. A systematic study of nanowires with extremely high coercivity above their magnetocrystalline anisotropy fields has opened a door to the solution of Brown’s Paradox. |
Eingeladen von | Dr. Thomas George Woodcock |
Kontakt | Martina Javorka |
Freitag 22.09.2023 | |
IMW-Seminar | 10:00 |
Ort | IFW Dresden B3E.26 |
Referent | Yuan Yu |
Thema | The design of thermoelectrics by tailoring chemical bonds and structural defects
Thermoelectric materials can generate clean electricity by the scavenging of waste heat and realize precise spot cooling by applying current. The performance of thermoelectric materials is determined by the intrinsic chemical bonding mechanism and the extrinsic manipulation of structural defects, both affecting the transport of electrons and phonons. An unconventional chemical bonding mechanism, named metavalent bonding, has been demonstrated unique to the high thermoelectric performance of many chalcogenides. Besides, lattice defects such as impurity clusters, Cottrell atmospheres, and interfacial complexions provide other freedoms to tune the thermoelectric properties in addition to traditional manipulations of the defect's dimensionality and density. In this talk, I will introduce metavalent bonding, experimental methods to characterize bonding and nano-chemistry of defects, as well as the correlations between these features and thermoelectric response.
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Eingeladen von | Dr. Ran He |
Kontakt | Martina Javorka |
Freitag 22.09.2023 | |
IMW-PhD Seminar | 13:00 |
Ort | IFW Dresden B3E.26 |
Referent | Abhijith Payattuvalappil |
Thema | A Novel Approach for the Detection of Chemical Order on a Local Scale in L10 Structures |
Eingeladen von | Prof. Kornelius Nielsch |
Kontakt | Dr. Anke Kirchner |
Der Dresdner Wissenschaftskalender unterstützt die interdisziplinäre Forschung in Dresden durch das Sammeln, Strukturieren und Verteilen von Ankündigungen anstehender wissenschaftlicher Gespräche über eine einheitliche Internetplattform. Es ermöglicht jedem, alle Seminarankündigungen zu durchsuchen und gefilterte Informationen zu abonnieren.
Zum Dresden Science Calendar
2023 | |
15. - 22. September | Summer School Spectroelectrochemistry, IFW Dresden |
17. - 23. September | Workshop "Magnetic Resonance of Correlated Electron Materials", IFW Dresden |
21. - 22. September | SAW Symposium 2023, Dresden |
2022 | |
30. Nov. - 1. Dez. | Joint Workshop IFW Dresden – University of Genoa „Superconducting and Topological Materials“, IFW Dresden |
6. - 7. Oktober | Treffen des Arbeitskreises „Intermetallische und oxidische Systeme mit Spin- und Ladungskorrelation“ der Deutschen Gesellschaft für Kristallwachstum und Kristallzüchtung e. V. |
4. - 5. Oktober | Kick-off Meeting THERMOS "Tellurium-Free Thermoelectric Modules by Interface Engineering", IFW Dresden |
26. - 27. Sept. | 19. GDS-Anwendertreffen, IFW Dresden (Flyer PDF) |
30. Aug. - 1. Sept. | Joint Workshop IFW Dresden – S.N. Bose National Center for Basic Sciences „Novel Magnetic and Topological Quantum Materials“ (Program PDF) |
29. Aug. - 2. Sept. | BIOREMIA Summer School, Ioannina / Griechenland |
28. Juni | Netzwerktreffen Additive-Drahtbasierte Fertigung: WirePrint // VEMAS-Anwenderworkshop, IFW Dresden |
1. Juni | UKRAPRO-Workshop: Condensed matter science assisted by machine learning, IFW Dresden |
31. Mai | 4. UKRATOP Workshop: Topological Phenomena in Quantum Materials, IFW Dresden |
06. - 07. April | Meeting Projekt "Sound of Ice", IFW Dresden |
2021 | |
14. - 15. Oktober | SAW Symposium |
14. Oktober | Abschiedskolloquium für Prof. Dr. Oliver G. Schmidt |
10. - 14. Oktober | BIOREMIA-Workshop "Science Communication and Presentation Skills", Dresden |
13. - 14. September | Internationale Konferenz: "Frustrated Magnetism and Topology", IFW Dresden |
25. - 27. Mai | Nature-Konferenz: Microrobots and Nanorobots for Biotechnology, online |
26. März | 3. UKRATOP-Workshop, online |
2020 | |
7. - 11. Dezember | BeMagic Training Workshop für Doktoranden des EU-Projekts BeMagic, online |
15. - 16. Oktober | SAW Symposium 2020 (verschoben auf Herbst 2020) |
29. Juni - 1. Juli | UKRATOP Days mit Vorträgen der Stipendiaten, virtuellen Labtours in ukrainischer Sprache und online- Workshop zu Topologischen Quantenmaterialien, IFW Dresden |
2. - 5. Juni | nature Konferenz: Microrobots & nanorobots for biotechnology, AGUV Akademie Dresden (verschoben: 25. - 27. Mai 2021) |
15. - 20. März | DPG-Frühjahrstagung, Dresden (abgesagt) |
10. - 11. Februar | Sächsischer Forschungs- und Vernetzungs-Workshop »Thermoelektrische Anwendungen in der Industrie«, Dorint Parkhotel Meißen |
23. - 24. Januar | BIOREMIA Kick-off Meeting , IFW Dresden |
2019 | |
25. - 27. September | Annual IFW Summer School for PhD students in Szczecin, Polan |
15. - 20. September | ECASIA19: 18th European Conference on Applications of Surface and Interface Analysis |
13. - 20. September | Summer School Spectroelectrochemistry, IFW Dresden |
20. - 21. Mai | International Workshop "Topology meets materials – Weizmann meets Dresden", IFW Dresden |
28. - 29. März | International Workshop "Quantum Dynamics, Transport, and Exotic Orders: Strolling among Spins and Strong Correlations", IFW Dresden |
28. - 29. März | Joint workshop of BAM Berlin and IFW Dresden, IFW Dresden |
2018 | |
4. - 5. Dezember | UKRATOP Workshop, IFW Dresden |
1. - 2. Oktober | SAW Symposium, Westin Bellevue Dresden, Germany |
28. - 30. August | Spin, waves & interactions 2018, Greifswald, Germany |
8. - 11. April | 667. WE-Heraeus-Seminar on System-oriented approach to thermoelectrics: Materials – Interfaces – Devices in Bad Honnef, Germany |
11. - 16. März | Joint Conference of the Condensed Matter Divisions of the DPG and EPS,
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1. Februar | Workshop of the DFG Priority Programme 1458 “High Temperature Superconductivity in Iron Pnictides“, IFW Dresden |
29. - 31. Januar | EPSQMat 2018: International Workshop on Electron and photon spectroscopies of quantum materials: status and perspectives, IFW Dresden |