Nuclear Magnetic Resonance Study of Co⁵⁹ in Y1-xGdxCo₂

The nuclear magnetic resonances of the Co 59 in Y 1- x Gd x Co 2 at 4.2, 77, 196 and 273 K have been observed for the gadlinium concentrations 0.1≦ x ≦1. The cobalt hyperfine field decreases monotonically from 61.4±1.0 kOe to 44.6±3.0 kOe by substituting the gadlinium sublattice of GdCo 2 with yttrium. The difference 16.8±4.0 kOe between 61.4±1.0 kOe and 44.6±3.0 kOe, is interpreted as the contribution of 4f electrons to the cobalt hyperfine field in GdCo 2 . The variation of the hyperfine field due to cobalt magnetic moment induced by gadolinium 4f electrons agrees fairly well with the variation of the Curie temperature as a function of the gadolinium concentration.