Evidence of dimensional crossover of the spin-glass transition in thinCuMn multilayers

We have used high-quality Cu₉₂{Mn}₈$/${Al}₂O₃ multilayers to investigate the shift in temperature and the change in scaling behavior of the spin-glass transition as a function of the layer thickness. In the thinnest CuMn layers (60 and 88 {}), the spin-glass exponents determined from the nonlinear susceptibility shift to new values, distinctly different from those for the bulk. These exponents are consistent with numerical studies of 2D spin-glass systems, suggesting that a 3D to 2D crossover occurs.