Dresden 2020 – wissenschaftliches Programm
Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 44: Topical Session: Interface-dominated phenomena - Solutes at Interfaces II
MM 44.2: Vortrag
Mittwoch, 18. März 2020, 17:30–17:45, IFW A
A quantum-mechanical study of clean and Cr-segregated antiphase boundaries in Fe3Al — •Martin Friák, Monika Všianská, and Mojmír Šob — Institute of Physics of Materials, Czech Academy of Sciences, Brno, Czech Republic
We present a quantum-mechanical study of thermodynamic, structural, elastic, and magnetic properties of selected antiphase boundaries (APBs) in Fe3Al with the D03 crystal structure with and without Cr atoms. The computed APBs are sharp (not thermal), and they have {001} crystallographic orientation. They are characterized by a mutual shift of grains by 1/2⟨100⟩, i.e., they affect the next nearest neighbors (APB-NNN type, also called APB-D03). Regarding clean APBs in Fe3Al, the studied ones have only a very minor impact on the structural and magnetic properties, including local magnetic moments, and the APB energy is rather low, about 80 mJ/m2. Interestingly, the studied APBs play a crucial role in the anisotropic (tensorial) elastic properties. The Cr atoms have a strong impact on magnetic properties and a complex influence on the energetics of APBs. The Cr atoms in Fe3Al exhibit clustering tendencies even in the presence of APBs and cause a transition from a ferromagnetic into a ferrimagnetic state. The impact of Cr atoms on APB energies in Fe3Al is found to be ambiguous, including reduction, having a negligible influence or increasing APB energies depending on the local atomic configuration of Cr atoms. As similarly contradicting trends were found in experiments, our results can shed a new light on these experimental data (see M. Friák, M. Všianská, M. Šob, Materials 12 (2019) 3954).