High resolution spatial analyses of trace elements in coccoliths reveal new insights into element incorporation in coccolithophore calcite.

Coccolithophores are phytoplanktonic algae which produce an exoskeleton made of single platelets of calcite named coccoliths. They are widespread in all oceans and directly impact the short- and long-term C cycle. The study of coccolith size, morphology and elemental composition reveals important information regarding the ability of the cell to calcify and on the factors that influence this process.

Structural Study of Nano-Sized Gahnite (ZnAlO): From the Average to the Local Scale.

Spinel gahnite (ZnAlO) has been obtained through a hydrothermal synthesis method with a grain size of about 2 nm. The sample was calcined for a few hours at two different temperatures (800 and 900 °C) in order to obtain larger grain sizes to be analyzed by means of powder diffraction with the Rietveld method, and by means of total scattering with the Pair Distribution Function (PDF) method. The idea is to compare the average to the local structure, as a function of increasing grain size.

The devitrification of artificial fibers: a multimethodic approach to quantify the temperature-time onset of cancerogenic crystalline phases.

A variety of artificial fibers extensively employed as lining in high-temperature apparatus may undergo a devitrification process that leads to significant changes in the chemical-physical properties of the materials. Among them, the crystallization of carcinogenic minerals, such as cristobalite, has already been documented for alumino-silicate ceramic fibers. Five fibrous samples with different compositions were treated over a wide range of temperatures (20-1500°C) and times (24-336 h) to investigate the rate and the crystalline phases that are formed as well their onset temperatures.

Twinning and structure of Eu(0.6)Sr(0.4)MnO3.

The crystal structure of europium strontium manganese trioxide, Eu(0.6)Sr(0.4)MnO3, has been refined using a multiply twinned single crystal containing six twin components.

Monoclinic La1-xBaxMnO3 (x=0.185) at 160 K.

Single-crystal X-ray diffraction has shown that lanthanum barium manganese trioxide, La0.815Ba0.185MnO3, is monoclinic (I2/c) below a first-order phase transition at 187.