A neutron polarisation analysis study of the spin-glass phase of Y(Al1-xFex)2

Diffuse neutron scattering with full polarisation analysis has been used to characterise the spin correlations in the extended spin-glass phase of the C15 Laves-phase compound, Y(Al1-xFex)2, at concentrations of x=0.25 and x=0.65. Whilst the nuclear diffuse scattering indicates weak anticlustering of Fe atoms on the Al sublattice, the magnetic scattering can be interpreted as arising from small ferromagnetic clusters of less than 10 A in diameter, with these continuing to exist at much higher temperatures than the spin-glass temperature. The ferromagnetic correlations which give rise to the clusters are short-range, and some evidence is found for weak antiferromagnetic correlations. (orig.)