Composition-Property Relations for GA FA MA PbI Perovskites.

Halide perovskites are materials for diverse optoelectronic applications owing to a combination of factors, including their compositional flexibility. A major source of this diversity of compositions comes from the use of mixed organic cations in the A-site of such compounds to form solid solutions. Many organic cations are possible for this purpose.

Piezoelectric Properties of PbLa(ZrTi)O Thin Films Studied by In Situ X-ray Diffraction.

The piezoelectric properties of lanthanum-modified lead zirconate titanate PbLa(ZrTi)O thin films, with = 0, 3 and 12 mol% La, were studied by synchrotron X-ray diffraction under direct (DC) and alternating (AC) electric fields, with AC frequencies covering more than four orders of magnitude. The Bragg reflections for thin films with low lanthanum concentration exhibit a double-peak structure, indicating two contributions, whereas thin films with 12% La possess a well-defined Bragg peak with a single component. In addition, built-in electric fields are revealed for low La concentrations, while they are absent for thin films with 12% of La.

Infrared spectroscopy: a tool for determination of the degree of conversion in dental composites.

Infrared spectroscopy is one of the most widely used techniques for measurement of conversion degree in dental composites. However, to obtain good quality spectra and quantitative analysis from spectral data, appropriate expertise and knowledge of the technique are mandatory. This paper presents important details to use infrared spectroscopy for determination of the conversion degree.

Setting time and thermal expansion of two endodontic cements.

The purpose of this study was to evaluate the setting time and the thermal expansion coefficient of 2 endodontic cements, MTA-Angelus and a novel cement called CER. The setting time was determined in accordance to ANSI/ADA specifications no. 57.