DPG Phi
Verhandlungen
Verhandlungen
DPG

Berlin 2015 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 24: Magnetic Materials I

MA 24.3: Vortrag

Mittwoch, 18. März 2015, 10:00–10:15, H 0112

Element-resolved thermodynamics of LaFe13−xSix — •Markus Ernst Gruner1,2,3, Werner Keune2,4, Beatriz Roldan Cuenya5, Claudia Weis2, Joachim Landers2, Sergey I. Makarov2, David Klar2, Michael Y. Hu6, Ercan E. Alp6, Jiyong Zhao6, Maria Krautz1, Oliver Gutfleisch7, and Heiko Wende21IFW Dresden — 2Universität Duisburg-Essen — 3Forschungs-Neutronenquelle FRM II, Garching — 4MPI Halle — 5Ruhr-Universität Bochum — 6Argonne National Laboratory — 7TU Darmstadt

By combination of two independent approaches, nuclear resonant inelastic X-ray scattering and first-principles calculations in the framework of density functional theory, we demonstrate an unusual and significant effect of the magnetic phase transition on the element-resolved vibrational density of states of LaFe13−xSix. This comprises the disapperance of a high-energy peak in connection with an overall softening of phonons in the paramagnetic phase, which is unexpected due to the large volume decrease at the transition. The pronounced magnetoelastic effect originates from adiabatic electron phonon coupling caused by specific changes in the electronic density of states at the Fermi level arising from the itinerant electron metamagnetism of Fe. The increase in lattice entropy associated with the Fe subsystem is significant and contributes cooperatively with the magnetic and electronic entropy changes to the excellent magneto- and barocaloric properties.

100% | Mobil-Ansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2015 > Berlin