Muon diffusion and electronic magnetism in Y2Ti2O7

We report a muon spin relaxation study in a Y2Ti2O7 single crystal. We observe slow local field fluctuations at low temperature which become faster as the temperature is increased. Our analysis suggests that muon diffusion is present in this system and it is small below 40 K and therefore incoherent. A surprisingly strong electronic magnetic signal is observed with features typical for muons thermally diffusing towards magnetic traps below approximate to 100 K and released from them above this temperature. We attribute the traps to Ti3+ defects in the diluted limit. Our observations are highly relevant to the persistent spin dynamics debate on R2Ti2O7 pyrochlores and their crystal quality.