Homogeneity range of the NaTl-type Zintl phase in the ternary system Li-In-Ag

摘要

The remarkably broad homogeneity range of the NaTI-type Zintl phase in the ternary phase diagram Li-In-Ag at room temperature was determined by structure evaluation using X-ray powder diffraction. The colours of the investigated Zintl phases correlate with the valence electron concentration (VEC) Lis already established for the quasibinary cut Li-0.5(InxAg1-x)(0.5) with 0.47 <= X <= 100, i.e. with decreasing VECs the colour changes from grey over reddish to bright yellow. All compounds in the new quasibinary cut Li-x(In0.5Ag0.5)(1-x) with 0.47 <= x <= 0.60 appear free from vacancies in the Li-sublattice, even for Li-deficient compositions. The partial occupation of Li-sites by excess Ag and In instead is in full agreement with the behaviour of the binary NaTl-type Zintl phases LixZn1-x and LixCd1-x (0.47 <= x <= 0.54) with a low VEC about 1.5. (c) 2005 Elsevier Inc. All rights reserved.