Structure, bonding, and properties of compounds in the Sc-rich part of the Sc-{Mn,Fe,Co,Ni,Pd,Pt}-Ga systems

Date

Apr 5, 2024

Time

10:00 AM - 11:00 AM

Speaker

Dr. Vitaliy Romaka

Affiliation

IFW Dresden

Language

en

Main Topic

Materialien

Host

Rita Taubert

Description

Although Sc shows outstanding technological potential in scandium-reinforced light alloys with good corrosion resistance, the Sc-containing systems with transition elements and gallium still lack information on the formation, structure, bonding, and properties of the corresponding Sc-rich ternary phases. Our recent investigation of the Sc-{Mn,Fe,Co,Ni,Pd,Pt}-Ga systems revealed the formation of a series of homologous compounds Sc54{M,Ga}17 for M = Mn, Fe, Co, Pd, and Pt, which appeared to be isotypic with the Hf54Os17-type structure (space group Immm). Most of these phases have limited homogeneity regions, while Sc54(Pt1-xGax)17 exhibits at 850°C a large homogeneity region (0<x<0.28) extending from Ga-rich Sc76Pt17.5Ga6.8 ≡ Sc54(Pt0.72Ga0.28)17 to novel binary Sc54Pt17. However, we observe an opposite effect against the usual trend of solid solution hardening, which is less pronounced for Sc54(Pd1-xGax)17 than for Sc54(Pt1-xGax)17. In addition to the detailed structural analysis of the two new compounds in the Sc-Co-Ga system: Sc50Co13Ga3 (space group F-3m), ε-Mg26-xAg7+x type, and Sc6Co1.73+x+yGa1-x (space group Immm; x=0.43; y=0.14), Ho6Co2Ga derivative type, we present a detailed study of chemical bonding, band structure, thermodynamic, magnetic, electrical, and elastic properties for all studied compounds and related kappa phases.

Links

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Last modified: Apr 5, 2024, 7:37:16 AM