Exchange fields at rare-earth sites in Rn+1Co3n+5B2n (R=Gd and Dy) compounds

Abstract

Spontaneous magnetization and paramagnetic susceptibility have been measured for the Rn+1Co3n+5B2n compounds with R=Y, Gd, and Dy and n=1, 2, and 3 in the temperature range from 4.2 up to 1000 K in fields up to 20 kOe. The data on the Gd system are analyzed based on the molecular field model. The exchange field at the Gd site from the Co sublattice is estimated. The averaged exchange field at T=0 K is estimated to be 101 T for n=1, 75T for n=2, and 56 T for n=3. Paramagnetic susceptibilities are fairly well expressed by the superposition of the Co- and the Gd-sublattice contributions. Other magnetic properties of the Y and the Gd system are also reported. Only magnetic data are given for the Dy system.