Magnetic, electronic and electron spin resonance studies of the (Gd_1-xY_x)Ni₂ compounds

Magnetization, electron spin resonance and heat capacity measurements have been made on the (Gd_1-xYx)Ni₂ compounds. Magnetization measurements reveal a moment deficiency for gadolinium in this series. In GdNi₂ a value of 6.92μ_B is obtained for the gadolinium moment, which decreases further with yttrium substitution. In the concentration range 0.2 ≤ x ≤ 0.8 the samples show features seen in inhomogeneous ferromagnets. The ESR measurements reveal a negative g-shift and a very shallow ESR bottleneck in this system. The specific heat of the samples in the concentration range 0.2 ≤ x ≤ 0.8 show complex behaviour: downturn at low temperatures in the usual (C/T) against T² graphs, anomalously large γ-values and so on. In the remaining compounds the specific heat shows normal behaviour. At the YNi₂ end of the series a rapid increase in the host density of state takes place when gadolinium is substituted for yttrium.