Ferroelectric Behavior In Fluorinated Aliphatic Polyurethanes

Fluorinated Polyurethanes, Synthesis and Properties.

Fluorinated polyurethanes with a glass transition temperature as low as -139 °C and a decomposition onset temperature of 247-330 °C were prepared by a reaction of fluorinated alcohols with aromatic and cycloaliphatic diisocyanates in solution or melt.

In vivo kinetic degradation analysis and biocompatibility of aliphatic polyester polyurethanes.

Polyester polyurethanes incorporating polyhedral oligosilsesquioxane (POSS) as the crystalline hard block were evaluated for biocompatibility and degradation over 24 weeks in vivo. In vitro studies were also used to predict the onset of mass loss. The molecular weight of each sample was found to decrease quickly over an 8 week period and then became constant due to the nondegrading POSS hard bl...

Impurity-induced ferroelectric relaxor behavior in quantum paraelectric SrTiO3 and ferroelectric BaTiO3

The ‘‘ferroelectric relaxor’’ behavior, which shows a rounded permittivity peak with low-frequency dispersion, was first observed by Smolenskii et al. in the Ba(Ti,Sn)O3 solid solution in 1954. Later, this phenomenon was also observed in Pb(Mg1/3Nb2/3)O3 ~PMN! compounds by the same group. Smolenskii et al. named this phenomenon as a behavior of the ferroelectric with diffuse phase transition ~D...

Spatial inhomogeneity of imprint and switching behavior in ferroelectric capacitors

Unusual behavior of the ferroelectric polarization in PbTiO3/SrTiO3 superlattices.

Artificial PbTiO3/SrTiO3 superlattices were constructed using off-axis rf magnetron sputtering. X-ray diffraction and piezoelectric atomic force microscopy were used to study the evolution of the ferroelectric polarization as the ratio of PbTiO3 to SrTiO3 was changed. For PbTiO3 layer thicknesses larger than the 3-unit cell SrTiO3 thickness used in the structure, the polarization is found to be...