The diluted antiferromagnet MnxMg1-xTiO3 transforms from the antiferromagne
t (AF) to the spin-glass (SG) system at x similar to 0.6. In order to study
the microscopic nature of spin dynamics and ordering, we performed muon sp
in relaxation measurements for the powder samples of x = 1.0 similar to 0.5
5 and examined the concentration dependence. From these results, a drastic
change in the spin dynamics was found to occur at x similar to 0.6.