The Y5−xMg24+x(1.08(4)≤x≤1.30(1)) series and a ternary derivative Ce6.9Y12.5(7)Mg92.2: A comparison of their crystal and electronic structures

Reported is the Mg-rich intermetallic compounds Y5−xMg24+x series adopting the cubic α-Mn type structure and its complex ternary derivative Ce6.9Y12.5Mg92.2 crystallized in a defect Sm11Cd45 type structure with a nearly twice larger lattice parameter than those of the Y5−xMg24+x series. Electronic structure calculations show nearly free electron like behavior, but with a distinctive pseudogap in the density of states curve for the ternary system.