  To clarify the magnetic properties of cluster-glass states in Sr1-xLaxRuO3
(0.3 <= x <= 0.5), we report herein the results of muon spin relaxation (muSR)
and neutron powder diffraction measurements. The muSR experiments showed that
magnetic clusters start developing well above the peak temperature T^* in the
ac susceptibility. The volume fraction of the magnetically ordered region
increases continuously with decreasing temperature, showing no anomaly at T^*,
and reaches nearly 100% at the lowest temperature. The temperature variation of
the volume fraction is essentially independent of the La concentration in the x
range presently investigated, although the dc magnetization is significantly
suppressed with increasing x. Neutron powder diffraction experiments revealed
that the ground state for x = 0.3 is a long-range ferromagnetic ordered state.
These results indicate that, with decreasing temperature, cluster-glass states
in Sr1-xLaxRuO3 gradually develop into long-range ferromagnetic ordered states
with decreasing temperature, and that the magnetic ordering process differs
strikingly from that expected for a conventional second-order ferromagnetic
transition.
