Muon spin relaxation in zero applied field has been used to study the ferromagnetism of the reentrant ternary alloy Pd${\mathrm{Fe}}_{0.0035}$${\mathrm{Mn}}_{0.05}$. The static linewidth below $T_C$ shows that Mn participates in the ferromagnetic ordering at $T_C$. The temperature dependence of the dynamic depolarization demonstrates that relatively slow fluctuations (${\tau }_{\mathrm{eff}\mathrm{\approxeq }{10}^{\mathrm{-}10}–{10}^{\mathrm{-}11}}$s) persist in the region between $T_C$ and the spin-glass temperature $T_g$. The transition at $T_C$ is marked by critical fluctuations of the Mn spins, but the glass transition at $T_g$ is not. A detailed analysis of the form of the dynamic depolarization function indicates that the muon does not occupy the interstitial sites nearest the Mn impurities.

• Received 3 March 1986

DOI:https://doi.org/10.1103/PhysRevB.34.1683