Full Aging in Spin Glass State of Y_0.90Na_0.10MnO₃

We study the decays of the thermoremanent magnetization in Y_0.90Na_0.10MnO₃ for different waiting times at the measuring temperature 33K, well below the spin glass (SG) transition temperature 42K. The results demonstrate that almost perfect full aging can appear even in the case of the cooling time as long as 700s from 60K to 33K. By subtracting the stationary component A(τ₀t)^a (A is a dimensionless constant, t represents the time, τ₀ is the microscopic spin flipping time, and α is a parameter always in the rang of 0.1-0.01), the value of α is found to be much smaller than that reported in other SG systems, which is well consistent with the behaviour of the ac susceptibility. All of them are discussed based on the intrinsic geometric magnetic frustration for the present system.