Spin relaxation in nanophased manganites

We present recent results obtained by DC and AC susceptibility, muon spin relaxation and neutron spin echo experiments in magnetically ordered La0.7Pb0.3MnO3 and disordered La0.7Pb0.3Mn0.8Fe0.2O3. These results aim to cover an extraordinary equivalent frequency range (from quasi-static experiments to almost the THz region) and give an overall picture of the processes within. The different relaxations observed are related either to the macroscopic long-ranged interactions among magnetic clusters (susceptibility techniques) and to short-ranged intracluster spin diffusion processes (muon and neutron techniques).