Peculiarities of the interaction of ytterbium with transition metals (Cr,Mn) and aluminium

Abstract

The isothermal sections of the Yb(Cr,Mn)Al phase diagram at 770 K have been constructed from X-ray powder diffraction phase analysis of arc-melted and annealed alloys. The Cr-based system contains three ternary compounds, YbCr2Al20 (CeCr2Al20 structure type), Yb6Cr4 + xAl43 − x (x = 1.76, new structure type) and YbCrxAl12 − x (x = 2.60–4.30, ThMn12 structure type), while the Mn-based system contains only two, YbMnxAl12−x (x = 2.86–4.55, ThMn12 structure type) and Yb6Mn4 + xAl43 − x (x = 1.76, Yb6Cr4 + xAl43 − x structure type). The immiscibility range between Yb and the transition element decreases more rapidly with increasing Al content in the Mn system than in the Cr system.