Phase separation in a spin-glass

We have performed an extended x-ray absorption fine structure measurement of the Mn environment in a ${\mathrm{Au}}_{0.95}$ ${\mathrm{Mn}}_{0.05}$ spin-glass. There is no evidence for changes in the Mn nearest neighbors with annealing, in spite of large changes in the magnitude of the cusp in the magnetic susceptibility. We propose a model based on phase separation which explains these apparently inconsistent observations in the context of the known structural and magnetic properties of the Au-Mn system. The effects of this annealing process on spin-glass behavior are discussed with reference to current theories.