Lattice spacings and stacking fault probabilities in Ag-Cd-In alloys

Abstract

Lattice spacing values in ternary Ag-Cd-In alloys containing 5 to 30 at. pct Cd and 5 to 15 at. pct In have been determined from X-ray powder patterns using the Nelson-Riley extrapolation procedure. The values are shown to lie, in a ternary plot, on iso-parameter lines obtained by joining equal lattice spacing values in the relevant binary alloys. The intrinsic stacking fault probabilities (α) in these alloys obtained from measurement of X-ray peak displacements are found to follow the empirical relation α=α₀ exp k|ΔZ| p, where α₀ is the intrinsic fault probability in Ag, |ΔZ| is the weighted mean of solvent-solute valence differences, p is the combined solute content, and k is a constant approximately equal to 0.08 in agreement with the value found earlier for binary alloys based on silver.