  We investigate the low temperature behaviour of
Pb(In$_{1/2}$Nb$_{1/2}$)O$_{3}$-Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$-PbTiO$_{3}$
using dielectric permittivity measurements. We compare single crystal plates
measured in the [001] and [111] directions with a polycrystalline ceramic of
the same composition. Poled crystals behave very differently to unpoled
crystals, whereas the dielectric spectrum of the ceramic changes very little on
poling. A large, frequency dependent dielectric relaxation seen in the poled
[001] crystal around 100 K is much less prominent in the [111] crystal, and
doesn't occur in the ceramic. Preparation conditions and the microstructure of
the material play a role in the low temperature dynamics of
relaxor-ferroelectric crystals.
