Direct observation of the near-surface layer inPb(Mg1∕3Nb2∕3)O3using neutron diffraction

Spatially resolved neutron diffraction as a function of crystal depth in Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3} reveals the presence of a distinct near-surface region where a strong distortion in the lattice exists. A dramatic change in both the lattice constant and the Bragg peak intensity as a function of crystal depth is observed to occur in this region over a length scale {approx}100 {mu}m. This confirms a previous assertion, based on a comparison between high-energy x rays and neutrons, that such a near surface region exists in the relaxors. Consequences to both single crystal and powder diffraction measurements and previous bulk neutron diffraction measurements on large single crystals are discussed.