Mechanical spectroscopy of atomic ordering in Fe-(16−21)Ga-RE alloys

• Published in: Journal of alloys and compounds 2021-05, Vol.864, p.158819, Article 158819
• Main Authors: Golovin, I.S., Palacheva, V.V., Mohamed, A.K., Cifre, J., Dubov, L.Yu, Samoylova, N.Yu, Balagurov, A.M.
• Format: Article
• Language: English
• Subjects: Alloying elements; Anelasticity; Atomic beam spectroscopy; Binary alloys; Erbium; Fe-Ga; Ferrous alloys; Gallium base alloys; Heating; High temperature; Internal friction; Magnetic measurement; Magnetization; Neutron diffraction; Ordering; Phase transitions; Positron annihilation; Rare earth alloys; Rare earth elements; Spectrum analysis; Transient effects; Vacancies; Ytterbium
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.158819

•The nature of two thermally-activated and two transient effects for Fe-19Ga-RE alloys is reported.•D03 ordering of A2 Fe-Ga solution is examined by several in situ methods.•Influence of RE elements on phase transformations is analysed. Anelasticity of Fe-(16−21)at% Ga-RE (rare earth RE = La, Tb, Dy, Er, Yb elements) alloys at room and elevated temperatures is studied in a sub-resonance mechanical spectroscopy. Two thermally-activated and two transient effects are recorded in most of the studied alloys. To explain these phenomena, structure and phase transitions in several binary and ternary Fe-Ga alloys are investigated. The D03 ordering of rapidly cooled alloys with the A2 structure at heating at around 300 °C and the disordering at heating and the D03 ordering at cooling around 500 °C for annealed samples are proved using three in situ techniques: neutron diffraction, vibrating sample magnetometry, and internal friction and supported by positron annihilation experiments. Thermally activated transitory effects are tentatively explained by stress-induced reorientation of Ga-Ga, vacancy-vacancy pairs, and carbon atoms jumps.