Publications

We present SQUID measurements of the nonlinear susceptibility χnl of “pure” CuMn and CuMn doped with gold impurities with concentrations CAu of 1, 2, and 3 at.%. Gold impurities suppress the magnitude of χnl. Ordinary one-parameter scaling with respect to field and temperature is obeyed by χnl of the pure CuMn. However, strong deviations from this scaling behavior are observed in the gold-doped samples in the vicinity of the freezing temperature and in low fields, H<H∗ where H∗increases with c. This is interpreted as the onset of an anisotropy-induced crossover from a Heisenberg to an Ising spin-glass critical behavior.