Third neighbour hyperfine field shift in a diluteNiAl alloy

In the binary Ni_98.5Al_1.5 alloy we observed well resolved satellite hyperfine fields at¹¹¹Cd nuclear probes. The hyperfine shifts derivated are −4.0(3); −8.5(3) and ⃛14.0(3)% relative to the pure nickel value. From the relative intensity of the four components as well as from the quadrupole interaction data we identify the satellites as impurity-probe configurations containing zero, one, two or three Al impurities in the third neighbour shell only. The third neighbour contribution to the hyperfine field at Cd in nickel equals ΔH ₃= +4.5kG/μ _B-atom, allowing an estimate ΔH ₁≃ −17.8 kG/μ _B-atom for the first shell contribution, confirmed by a similar experiment on Ni_98.5Pd_1.5.