The low-field electrical behavior of relaxor ferroelectric ceramics has been qualitatively described by many parameters, including diffuseness (6), which characterizes the breadth of the transition peak and is roughly related to the standard deviation of the peak. Three major types of equations have been used to calculate 6: Gaussian distribution (originated by Smolenskii and Rolov et d.), power law (used by many authors), and variable power law (Uchino et al). In this work, the three calculational techniques are compared analytically and illustrated using dielectric data from ceramic 0.88Pb(Mg1,3Nbzi3)03. 0.12PbTi03. All three methods of analysis result in very linear plots; however, the calculated values of S are significantly different. A method of limitingthe temperature range to that corresponding to 2/3 of the maximum relative dielectric constant is suggested in order to decrease the deviations. This limitation is shown to give consistent reproducible diffuseness values without extraneous contributions arising from the relaxor nature of the material or from differing temperature ranges of measurement, thus allowing 6 to be used as an effective comparative parameter for relaxor ceramics. [

Ferroelectric photoactive suspensions for stereolithography have been developed by dispersing a high volume fraction of barium titanate powder in hexanediol diacrylate (HDDA) with the aid of effective photoinitiators and dispersants. Rheological properties showed a shear thinning behavior and a low viscosity at a shear rate adequate for the recoating process. The barium titanate-HDDA suspension showed poor curing behavior due to the large refractive index difference between the ceramic and the resin. The coarse barium titanate-HDDA suspension showed a smaller surface reflectance and a larger cure depth than the fine barium titanate-HDDA suspension.

We report the fabrication of membranes hundreds of micrometers thick that demonstrate efficient electron conduction and proton transport through vertically aligned arrays of multiwalled carbon nanotubes (NTs) impregnated by epoxy. Electrical transport was Ohmic with a conductivity of 495 mS cm(-1). Protons traversed the membrane through the NT bore with a current of 5.84 × 10(-6) A. Good electron and proton transport, chemical robustness, and simple fabrication suggest NT membranes have potential in artificial photosynthesis applications.

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