The Magnetic Properties of GdCo₂ Compound and Its Hydrides

Abstract

The measurements of the magnetization and the hyperfine fields at ⁵⁹Co nuclei were performed in GdCo₂ and its hydrides (GdCo₂H_y). The results of the magnetization measurement show that hydrogen absorption leads to a drastic reduction (46–77%) in the magnetic moment per Co atom. This reduction can be interpreted as due to two contributions. The one is an electron transfer in the direction H atom→Co atom and the other is a change of the exchange interaction on the Co atom. On the other hand, the hyperfine fields at ⁵⁹Co nuclei undergo a smaller reduction (18–21%) as compared with a change in the Co moment upon hydrogen absorption. This reduction is discussed in terms of contributions of nearest neighbour Co and Gd atoms to the own Co atom.