  We report a neutron scattering study of the ferroelectric phase transition in
Sr$_{0.585}$Ce$_{0.025}$Ba$_{0.39}$Nb$_2$O$_6$ (SBN-61:Ce). We find no evidence
for a soft transverse optic phonon. We do, however, observe anisotropic diffuse
scattering. This scattering has inelastic and elastic contributions. In the
paraelectric phase the susceptibility associated with the elastic diffuse
scattering follows well the anomaly of the dielectric susceptibility of
SBN-61:Ce. In the ferroelectric phase the lineshape of the elastic scattering
is consistent with the form expected for the ferroelectric domain walls. In
contrast to the macroscopic observations, the scattering properties of Ce-doped
crystal do not exhibit important changes with respect to those of pure
Sr$_{0.61}$Ba$_{0.39}$Nb$_2$O$_6$.
