Exchange Interactions and Magnetocaloric Effects in Rare-Earth-Transition Metal Compounds

The magnetic properties and magnetocaloric effects of the (GdxY1-x)(n+1)Co3n+5B2n compounds with n=2 and n=3 are reported. The saturation mean cobalt moments are strongly dependent on composition, while effective cobalt moments are nearly constant for a given series. The ratio between the number of cobalt spins determined from effective moment and that obtained from saturation data shows a linear trend on the reciprocal exchange field. Maxima values of entropy changes are dependent on composition, being located between 30 K and 150 K. Very high values of relative cooling powers were shown.