Aging, rejuvenation, and memory effects in short-range Ising spin glass: Cu_0.5Co_0.5Cl₂-FeCl₃ graphite bi-intercalation compound

Non-equilibrium aging dynamics in 3D Ising spin glass Cu _0.5Co_0.5Cl₂-FeCl₃ GBIC has been studied by zero-field cooled (ZFC) magnetization and low frequency AC magnetic susceptibility (f = 0.05 Hz), where T_g = 3.92±0.11 K. The time dependence of the relaxation rate S(t) = (1/H)dM_ZFc/dln t for the ZFC magnetization after the ZFC aging protocol, shows a peak at a characteristic time t_cr near a wait time t_w, (aging behavior), corresponding to a crossover from quasi equilibrium dynamics to non-equilibrium. The time t_cr strongly depends on t_w, temperature (T), magnetic field (H), and the temperature shift (ΔT}. The rejuvenation effect is observed in both X′ and X″ under the T-shift and H-shift procedures. The memory of the specific spin configurations imprinted during the ZFC aging protocol can be recalled when the system is re-heated at a constant heating rate. The aging, rejuvenation, and memory effects observed in the present system are discussed in terms of the scaling concepts derived from numerical studies on 3D Edwards-Anderson spin glass model.