  Evidences of a monoclinic phase in unpoled (PbMg1/3Nb2/3O3)1-x-(PbTiO3)x with
x=0.35 (PMN-PT 35%) and unpoled (PbZn1/3Nb2/3O3)1-x-(PbTiO3)x with x=0.09
(PZN-PT 9%) are presented from a neutron Rietveld analysis. This monoclinic
phase is different from the phase recently evidenced by Noheda and coworkers in
PbZr1-xTixO3 with x=0.481 but is identical to the phase observed in poled
PZN-PT with x=0.102 by the same authors. The structural resolutions allowed us
to compare both structures and to deduce the direction and magnitude of
polarization. In PMN-PT 35% and PZN-PT 9% this phase is characterised by a weak
value of polarization, a strong deformation of oxygen polyhedra and weak
cationic shifts.
