New orthorhombic derivative of CaCu5-type structure: RNi4Si compounds (R=Y, La, Ce, Sm, Gd–Ho), crystal structure and some magnetic properties

The crystal structure of new YNi4Si-type RNi4Si (R=Y, La, Ce, Sm, Gd–Ho) compounds has been established using powder X-ray diffraction. The YNi4Si structure is a new structure type, which is orthorhombic derivative of CaCu5-type structure (space group Cmmm N 65, oC12).GdNi4Si and DyNi4Si compounds order ferromagnetically at 25 and 19K, respectively whereas YNi4Si shows antiferromagnetic nature. At 15K, DyNi4Si shows second …