RMX COMPOUNDS FORMED BY ALKALINE-EARTHS, EUROPIUM AND YTTERBIUM .2. TERNARY PHASES WITH M = ZN, CD AND X = SI, GE, SN, PB

25 new RMX phases (R = Ca, Sr, Ba, Eu, Yb; M = Zn, Cd; X = Si, Ge, Sn, Pb) were found to crystallize in the structure types ZrBeSi, LiGaGe, TiNiSi, ZrNiAl and CeCu2. Single-crystal refinements were made for YbZnSn (LiGaGe type) with complete atomic ordering, and for SrCdSn, BaCdSn and BaCdPb with disordered CeCu2 structure. A two-dimensional structural map is proposed accounting for 83 RMX phases formed by alkaline earths, europium and ytterbium with the same valence electron concentration (8/3 electrons per atom).