Spin dynamics in a site diluted finite spin cluster system probed by positive muons

The site diluted finite spin cluster system Rb2CO x Mg1−xF4 (x=0.15, 0.4, 0.5) has been investigated by the μ+SR technique. Muon spin relaxation was observed in these diluted magnetic systems in a weak longitudinal field of 100 G. By reducing temperature below 100 K, the experimental data show features of slowing down phenomena of the Co electron moments in the finite spin clusters.