The role of crystal chemistry in YbCu5−xAux

Abstract The role of crystal chemistry in YbCu 5− x Au x crystallizing in the FCC AuBe 5 -type structure is highlighted through the study of the 0.7 ⩾  x  ⩾ 0.4 region. Magnetic frustration, due to the magnetic Yb-ions forming a network of edge-sharing tetrahedra, seems to play an important role in the evolution of the ground state of the system. Significant differences are found among the YbCu 5− x Au x compounds compared to the cubic isotypic systems YbCu 5 − x Ag x and YbCu 5 .