Crystal structure and magnetic properties of novel R3Co2.2Si1.8 compounds (R=Y, Gd–Tm)

The crystal structure of new ternary Dy3Co2.2Si1.8 compound has been established using single crystal X-ray diffraction, and those of R3Co2.2Si1.8 phases (R=Y, Gd–Tm) phases have been verified through the powder diffraction techniques. The Dy3Co2.2Si1.8 structure is a new structure type, which is obtained from the Er3Ge4 with an ordered Er3Ge4-type structure (space group Cmcm) one by coloring the two Ge sites, 4a and 4c, with Si and the 8f site with Co atoms. Tb3Co2.2Si1.8, Dy3Co2.2Si1.8, Ho3Co2.2Si1.8 and Er3Co2.2Si1.8 compounds display ferromagnetic-type ordering.