Papers by Author: Cecile Napierala

Abstract: The reversible charge ordering transition of (Sm1-x,Cax)MnO3 is associated with strong changes in electrical, magnetic and infrared properties. In this work, normal spectral emissivity is calculated from infrared reflectance of bulk polished ceramics, measured by Fourier Transform Infrared Spectroscopy (FTIR). Emissivity versus temperature shows a sharp transition at the charge ordering transition. By comparing the apparent temperature of the sample with the absolute temperature, we show that (Sm1-x,Cax)MnO3 is a good candidate for infrared furtivity around room temperature.

Abstract: Nd0.3Sm0.7NiO3 ceramic has been synthesised using a sol-gel method and annealing at oxygen pressure. Nd0.3Sm0.7NiO3 exhibits a reversible metal insulator phase transition which is, in the infrared range, responsible of a thermal-optical contrast. Samples are structurally characterized by X-ray diffraction and thermogravimetric analysis. The Nd0.3Sm0.7NiO3 thermal – optical contrast is characterized in the mid-infrared range, using reflectance and thermal-optical measurements.