Transition between the relaxor and ferroelectric states for (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 with x=0.2 and 0.3 polycrystalline aggregates -: art. no. 082910

The transition between the relaxor and ferroelectric states for 0.8Pb(Mg1/3Nb2/3)O-3-0.2PbTiO(3) and 0.7Pb(Mg1/3Nb2/3)O-3-0.3PbTiO(3) polycrystalline aggregates has been studied by measurements of the dielectric and elastic properties as a function of temperature. The ferroelectric to relaxor transition seems to present a regime of ferroelectric fluctuations that is sharply interrupted by the appearance of the polar nanodomains. It also presents thermal hysteresis, not only in the transition temperature, T-c, but in the characteristic time scale of the ferroelectric fluctuations that is longer on cooling than on heating. The latter effect is much more significant for 0.8Pb(Mg1/3Nb2/3)O-3-0.2PbTiO(3) (T-c=346 K on heating), than for 0.7Pb(Mg1/3Nb2/3)O-3-0.3PbTiO(3) (T-c similar to 408 K on heating). This indicates that there is a sharp slowing down of the kinetics of the phase transition below 346 K. (c) 2005 American Institute of Physics.