Phase equilibria in the Er-Co-In system and crystal structure of Er8CoIn3 compound

Abstract

AbstractIsothermal section of the Er-Co-In system at T = 870 K was constructed by means of X-ray powder diffraction, microstructure, and EDX-analyses. Twelve ternary compounds, namely ErCoIn5 (HoCoGa5-type), Er6Co17.92In14 (Lu6Co17.92In14-type), ErCo4In (MgCu4Sn-type), Er2CoIn8 (Ho2CoGa8-type), Er10Co9In20 (Ho10Ni9In20-type), Er3Co1.87In4 (Lu3Co1.87In4-type), ErCoIn, Er11Co4In9 (Nd11Pd4In9-type), Er11Co3In6, Er8CoIn3 (Pr8CoGa3-type), Er6Co2.19In0.81 (Ho6Co2Ga-type), and Er13.83Co2.88In3.10 (Lu14Co2In3-type) exist in the Er-Co-In system at this temperature. The crystal structure of the Er8CoIn3 compound was determined by means of X-ray powder method (Pr8CoGa3-type, P63mc space group, a = 1.02374(2) nm, c = 0.68759(2) nm). Almost none of the binary compounds dissolve the third component. The exception is the existence of the solid solution based on ErCo3 binary compound, which dissolves up to 8 at.% of In.