FINITE-SIZE EFFECTS IN THIN NIMN SPIN-GLASS LAYERS

Measurements of the normalized spin freezing temperatures, T-f/T-f(b), (T-f(b)=bulk spin-freezing temperature) are reported for NiMn/Cu mult ilayers in which the Mn concentrations are in the spin-glass range and the Cu thickness is held constant at a large enough value (t(Cu)=30 n m) to magnetically decouple the NiMn layers. The variation of T-f/T-f( b) with NiMn layer thickness, t(NiMr), is very similar to the variatio ns previously found for CuMn, AgMn, and AuFe. Quasistatic finite size effects in NiMn spin-glass thus appear to be rather similar to those i n the more traditional noble-metal spin gf as ses. (C) 1996 American I nstitute of Physics.