  The mixed-valence perovskitelike manganites are characterized by unique
interrelation of Jahn-Teller distortions, electric and magnetic properties. The
Jahn-Teller distortion follows the Mn(3+)->Mn(4+) charge transfer with some
delay. Its development depends on the lifetime of Mn in (3+) state, governed by
the Mn(4+)/Mn(3+) ratio and magnetic correlation. The non-coherence of
Jahn-Teller distortions in orthorhombic mixed-valence manganites and
rhombohedral RMnO3 (R = rare earth) results in oxygen disorder. We demonstrate
that the Raman spectra in this case are dominated by disorder-induced bands
reflecting the oxygen partial phonon density of states (PDOS). The PDOS origin
of the main Raman bands in insulating phases of such compounds is evidenced by
the similar lineshape of experimental spectra and calculated smeared PDOS and
disappearance of the PDOS bands in ordered ferromagnetic metallic phase.
