Aging as Domain Growth in the Spin Glass Copper Manganese*

We report on dynamical measurements on a 4.5nm thin film of the spin glass, Cu_0.88Mn_0.12, as well as a bulk sample of Cu_0.96Mn_0.04. Systematic measurements of the waiting time effect on the thermoremanent magnetization (TRM) of both samples at temperatures approaching their freezing and glass temperature respectively were performed. The process of aging between the film and the bulk is found to differ substantially. In the thin film sample, the S(t) character of the TRM is absent at temperatures between 14K and T_f. By the use of the value of the TRM after a standard measuring time, it is found that the waiting time effect is absent at temperatures between 0.9T_f - T_f. This is in contrast with aging in the bulk sample. While the S(t) character of the TRM is evident all temperatures in the bulk, the S(t) curves gradually collapse onto one another between the temperatures of 0.90T_g – 0.96T_g. These observations are examined in light of the spin glass correlation length, ξ(t, T), from nucleation to length scales comparable to either the thin film thickness L in the film or the size of crystallites in the bulk.