  Detailed analyses of the temperature-dependent zero field ac susceptibility
of prototypical phase-separated (La1-yPry)0.7Ca0.3Mn16/18O3, 0 < y < 1, reveal
features consistent with the presence of a Griffiths phase (GP), viz., an
inverse susceptibility characterized by power law with 0.05 < lamda < 0.33 as y
decreases towards yc < 0.85. Beyond yc = 0.85, the GP is suppressed. These
data, combined with previous neutron diffraction measurements, enable a phase
diagram summarizing the evolution of the GP with composition to be constructed
for this system; in particular, it shows that the disorder relevant for the
establishment of such a phase is linked closely to the relative volume
fractions of the phase separated antiferromagnetic and ferromagnetic
components, even when the recently estimated double exchange (DE) linked
percolation threshold is exceeded. The influence of electron-phonon coupling
can also be seen through oxygen isotope effects.
