Antiferromagnetism of Disilicides of Heavy Rare Earth Metals

Magnetic properties of disilicides of Gd, Tb, Dy, Ho, and Er have been investigated at temperatures ranging from 4.2°K to room temperature. All the disilicides except ErSi 2 have the orthorhombic ThSi 2 type of crystal structure and are shown to be antiferromagnetic. The Néel temperatures of GdSi 2 , TbSi 2 , DySi 2 and HoSi 2 are 27°K, 17°K, 17°K, and 18°K, respectively. The compound ErSi 2 has the hexagonal AlB 2 type of crystal structure and is paramagnetic at above 4.2°K. The paramagnetic Curie temperature of these compounds decreases with the number of f electrons of the rare earth ion.