Phase Transition of SBN: Ce Studied by Anisotropic Holographic Scattering

Dynamic Light Scattering at Domains and Nanoclusters in a Relaxor Ferroelectric

“…A similar phenomenon was observed by Chen et al [15] on SBN61:Ce (x 0.005) in the millisecond regime, which was interpreted in terms of focusing and defocusing due to a "thermal lens" effect. Since our oscillations take place on a long time scale, we rather propose a holographic light scattering effect [16] in view of the well-known photorefractive properties of SBN [10,14]. In our experiment the HeNe-laser light writes and detects gratings which are due to interference of the primary light beam with parasitic Rayleigh scattered light.…”

Conical light scattering in strontium barium niobate crystals related to an intrinsic composition inhomogeneity

“…Conical light scattering, i.e. scattering of an incident coherent light beam onto the surface of a cone, has been reported for natural crystals of tourmaline [1], polar oxides including doped LiNbO 3 [2,3] or Sr 0.61 Ba 0.39 Nb 2 O 6 (SBN) [4], and for molecular crystals of Na 2 [Fe(CN) 5 NO]•2H 2 O [5] as well. A strict dependence of the cone apex angle on the angle of the incident probe light with respect to the crystal system is distinctive.…”

“…The scattering is ascribed to the interaction of the incident light wave with a refractive-index inhomogeneity on the micro-scale in the crystal bulk. The origin of the related refractive-index inhomogeneity, however, is due to either impurity ions (scattering ring in tourmaline [1]), the presence of intrinsic (non-collinear frequency doubling [3,6] or photoinduced ferroelectric domains [7]) or to volume phase gratings recorded via the photorefractive effect ('Venetian blind' effect [8], or polarization-anisotropic photoinduced light scattering [4]). The relation of conical light scattering to ferroelectric domains has enabled phase transition studies of the relaxor-ferroelectric SBN:Ce by determining the scattering intensity as a function of temperature [4].…”

“…The origin of the related refractive-index inhomogeneity, however, is due to either impurity ions (scattering ring in tourmaline [1]), the presence of intrinsic (non-collinear frequency doubling [3,6] or photoinduced ferroelectric domains [7]) or to volume phase gratings recorded via the photorefractive effect ('Venetian blind' effect [8], or polarization-anisotropic photoinduced light scattering [4]). The relation of conical light scattering to ferroelectric domains has enabled phase transition studies of the relaxor-ferroelectric SBN:Ce by determining the scattering intensity as a function of temperature [4]. Further, the apex angle of the scattering cone was applied to determine the Li/Nb ratio of Fe-doped LiNbO 3 crystals [2] and the composition inhomogeneity of Mg-doped LiNbO 3 samples [3].…”

Photorefractive parametric scattering in the ferroelectric relaxor SBN: Phenomenological and application aspects

“…Because of its photorefractive origin, light-induced scattering contains information about electric charge transport mechanisms and various material constants, and therefore is an effective tool for contactless characterization of materials. [4][5][6][7] Light-induced scattering is seeded by coherent optical noise originating from optical inhomogeneities of the crystal. These seed waves interfere with pump waves of the transmitted part of the incident light.…”