Diffuse neutron scattering study of a disordered complex perovskite Pb(Zn1/3Nb2/3)O-3 crystal - art. no. 212101

Diffuse scattering around the (110) reciprocal lattice point has been inves tigated by elastic neutron scattering in the paraelectric and relaxor phase s of the disordered complex perovskite crystal Pb(Zn1/3Nb2/3)O-3 (PZN). The appearance of a diffuse intensity peak indicates the formation of polar na noregions at temperature T*, approximately 40 K above T-c=413 K. The analys is of this diffuse scattering indicates that these regions are in the shape of ellipsoids. more extended in the < 111 > direction than in the < 001 > direction. The quantitative analysis provides an estimate of the correlatio n length xi, or size of the regions, and shows that xi (< 111 >) similar to 1.24 xi (< 001 >), consistent with the primary or dominant displacement of Pb leading to the low-temperature rhombohedral phase. Both the appearance o f the polar regions at T* and the structural transition at T-c are marked b y kinks in the xi (< 111 >), curve but not in the xi (< 001 >) one, also in dicating that the primary changes take place in a < 111 > direction at both temperatures.