Stacking variants of the FebCrB types in the pseudobinary systems CaCu 1− xAg x and CaCu 1− xZn x

Abstract

Series of compounds which can be considered as stacking variants of the FeBCrB types are present in CaCu 1− x Ag x and CaCu 1− x Zn x . Three structural types occur in CaCu 1− x Ag x : the β-CaCu type for x ⩽ 0.05, a new stacking variant ( hc 4) 2 for 0.05 < x ⩽ 0.30 and the CrB type for x > 0.30. Five structural types occur in CaCu 1− x Zn x : the β-CaCu type for x < 0.025, the high temperature TbNi type for 0.025 < x < 0.15, a new stacking variant ( h 3 c) 2 for 0.15 < x ⩽ 0.30, the FeB type for 0.30 < x ⩽ 0.95 and the CrB type for CaZn. Whereas a regular variation of the percentage of hexagonal stacking from 40% to 20% to zero is observed in CaCu 1− x Ag x , the sequence 40%, 33%, 75%, 100%, zero occurs in CaCu 1− x Zn x ; this may be related to changes in electron concentration effects.