Giant moments in paramagnetic Pd-Ni alloys

The magnetizations of several paramagnetic Pd-Ni alloys were measured between 2.4 and 100 ^∘{}K in fields up to 56 kOe. For the alloys of up to {~}1.8-at.% Ni, it is deduced from the high-field and low-field behavior that stable giant moments ({~}18μB) are nucleated by groups of three or more nearest-neighbor Ni atoms. However, the spin number associated with each giant-moment complex is quite small ({~}2). The isolated Ni atoms and the nearest-neighbor Ni pairs simply make large exchange-enhanced contributions to a relatively temperature-independent component of the susceptibility. At a higher Ni concentration ({~}1.9 at.%), a departure from this simple situation is seen to emerge.