Abstract
In this work, Raman spectra and dielectricity–temperature dependence measurements were used to investigate the B-site order degree in CuO-doped Pb(Mg1/3Nb2/3)O3–PbTiO3 ferroelectric ceramics. The measurement results indicated a typical relaxor characteristic for all samples. With the increasing of CuO doping content, the B-site order degree increased first and then decreased. However, the frequency dispersion and the relaxation degree decreased first and then increased while the CuO addition content was increasing, which was thought to be strongly correlated with the variations of the B-site order. The opposite variation tendency of the B-site order degree and the relaxation degree revealed that the phase transition dispersity is closely related to the order–disorder behaviors.