Models for μ+ depolarization in spin glasses reflecting dynamical processes

The muon spin depolarization function is calculated for different dynamical processes. Muon diffusion is shown to cause motional narrowing at high temperatures (T>>Tsub(f) = freezing temperature of the spin glass) as well as at low temperatures (T<Tsub(f)), where the static line is essentially Lorentzian due to the randomness of the spin distribution of the dilute system. Different models of μ+ depolarization reflecting the freezing process of the spin glass system above Tsub(f) consider single correlation times as well as wide distributions of correlation times. It will be shown that the μSR depolarization investigated in transverse external fields does not enable one to distinguish between single correlation times and wide correlation time distributions. Therefore, an interpretation of the spin dynamics requires a comparison of TF-μSR with results of different measuring methods. (Auth.)