The high-pressure structure of (1-x)Na Bi TiO -xBaTiO at the morphotropic phase boundary.

The pressure-induced structural changes in the perovskite-type (ABO ) ferroelectric solid solution (1-x)Na Bi TiO -xBaTiO (NBT-xBT) at the morphotropic phase boundary (MPB) ( ) have been analyzed up to 12.3 GPa by single-crystal x-ray diffraction with synchrotron radiation. A pressure-induced phase transition takes place between 4.

The role of local non-tetragonal polar displacements in the temperature- and pressure-induced phase transitions in PbTiO-BiMeO ferroelectrics.

In situ high-pressure/high-temperature Raman-scattering analyses on PbTiO , 0.92PbTiO 0.08Bi(Zn Ti )O and 0.

Stochastic Polarization Instability in PbTiO_{3}.

Although discussions of structural phase transitions in prototypical ferroelectric systems with the perovskite structure, such as BaTiO_{3} and PbTiO_{3}, started almost seventy years ago, an atomic-level description of the polar characteristics as a function of temperature, pressure, and composition remains topical. Here we provide a novel quantitative description of the temperature-driven local structural correlations in PbTiO_{3} via the development of characteristic relative cationic shifts. The results give new insights into the phase transition beyond those reliant on the long-range order.

Multistep coupling of preexisting local ferroic distortions in PbTiO above the Curie temperature.

Temperature-dependent Raman spectroscopic analyses were performed for the prominent ferroelectric PbTiO in the temperature range 130-1040 K, focusing particularly on its paraelectric state above the Curie temperature [Formula: see text] K. The temperature evolution of the anomalous Raman scattering reveals that not only local ferroic distortions persist at temperatures well above [Formula: see text], but also there is a sequence of different coupling processes preceding the appearance of long-range ferroelectric order at [Formula: see text]. Our results indicate that, similar to relaxor ferroelectrics, the paraelectric phase of PbTiO can be considered as an ergodic system of local ferroic distortions, which only on average appears to have cubic symmetry.

The effect of osteoblasts on the surface oxidation processes of biodegradable Mg and Mg-Ag alloys studied by synchrotron IR microspectroscopy.

High-resolution analytical methods, including synchrotron infrared microspectroscopy combined with wavelength-dispersive X-ray emission spectroscopy were applied to study the structure and chemical composition of the oxidized layer of pure and Ag-alloyed Mg exposed to cell culture media without and with osteoblasts. Comparative analysis has been done on pure Mg immersed in two different cell culture media: Dulbecco's Modified Eagle's Medium (DMEM) and Roswell Park Memorial Institute medium (RPMI), whereas Mg-xAg binary alloys (x = 2, 4, 6, 8 wt%) were studied after immersion in DMEM. It is shown that the physicochemical formation of degradation products as well as the activity of the biological component is influenced by the addition of silver.