The dielectric properties of the terpolymer were also
measured after being subjected to an electric field of
100 MV/m at 50◦C for 10 min, similar to the poling
conditions applied to the copolymer. There is essentially
no change in the dielectric βr process before and after
the application of the electric field, which is expected
for the ferroelectric relaxor poled at temperatures where
the slim polarization loop is observed. This supports
complete conversion to the ferroelectric relaxor phase in
this terpolymer