Thermo-Remanent Magnetization (TRM) Explorations near the Critical Spin Glass Temperature*

We have performed extensive TRM measurements from .8Tg to .97Tg,  in a single crystal CuMn(6%) sample, over a wide range of waiting times (300 s to 100,000 s) and magnetic fields (3G-96G). We find a collapse of both the remanent magnetization, and the effective waiting time, as Tg is approached. This collapse suggests that we are observing the effects of critical fluctuations associated with the spin glass phase transition, and we probe several different scenarios to explain the data.