Anisotropy of electric field frezing of the relaxor ferroelectric Pb(Mg1/3Nb2/3)O3

The ferroelectric E-T phase diagram of relaxor ferroelectrics depends on the way the ferroelectric transition lines are approached. Here, we present the E-T phase diagram of relaxor Pb(Mg(1/3)Nb(2/3))O(3) where the temperature was held constant and the electric dc bias field applied along the [111] and [001] directions was varied. Strong anisotropy was observed for both directions. For the [111] direction, the critical point was shown to exist at practically the same field as in the E=const, T=variable case, whereas no critical point could be determined for the [001] direction for vertical bar E(bias)vertical bar < 20 kV/cm. When the electric field was applied along the [111] direction, a strongly nonlinear first-order-type jump in the polarization due to the cooperative ordering transition was observed. In the [001] direction, on the other hand, only a smooth field dependence of the polarization was found, indicating the lack of cooperative ordering.