Aging behavior of spin glass fine particles in restricted space

We examined the isothermal aging in spin glass AuFe fine particles so as to study the length scale of droplet in comparison with the particle size. Relaxation rates S in spin glass AuFe fine particles were obtained at 15, 28 and 32 K. A peak in S was observed at the observation time corresponding to the waiting time at 15 K, but it was observed at a time shorter than the waiting time at 28 K. The waiting time dependence of S is weakened at 32 K. This suggests that the droplet size increases up to the particle size and the growth successively stops at high temperatures.