PAPIN , Eric

Az alumínium-oxid alapú kerámiaanyagok tekinthetok az elsö modern kerámiáknak, melyek mind technológíai mind tudományos szempontból kiemelkedö fontosságúak. Feldolgozási technológiájuk és tulajdonságaik javulása igen szoros kapcsolatban van a szinterelésük mechanizmusára vonatkozó ismeretek bóvülésével1. A szinterclés a szilárd anyagok...

Alpha alumina powders have been produced by thermal treatment under controlled atmosphere of highly pure gamma alumina. The influence of the atmosphere and the addition of dopants (Mg2+, Cr3+, Th4+) were studied by thermoluminescence (TL). TL is a technique which gives information about point defects. It allowed to reveal the presence of oxygen...

Doped alpha-alumina powders have been synthesised by thermal treatment of gamma-alumina under a controlled atmosphere. Two TL peaks, located at 200°C and 365°C, have been detected in almost all samples. Their intensity is strongly dependent on the atmosphere and on the nature of introduced dopants. The influence oh these parameters on point...

The thermoluminescence method (TL), or the thermostimulated luminescence is one of the techniques which correlate thermal and optical methods and usually used to characterize the defects occuring in insulating or semiconductors materials. After a brief description of the TL phenomenon based on the example of alpha alumina, we present some...

Pure alpha alumina powders have been synthesized under oxidizing or reducing atmosphere. They have been characterized by specific surface area measurements, scanning electron microscopy and X-Ray diffraction. No differences have been detected. However the sintering rate of these powders depends on the synthesis atmosphere. The densification of...

Pure Al2O3 powders have been prepared by thermal decomposition of ammonium alum (NH4Al(SO4)2. 12H2O). The calcinations were performed at different temperatures, and under flowing oxygen or nitrogen or hydrogenated argon. The thermoluminescence of these powders after X ray irradiation at room temperature is studied from room temperature to 780...

Several alpha-Al2O3 samples were studied in order to determine the mechanism of electron-hole processes of the 430 K (D') thermoluminescence (TL) and thermally stimulated exoelectron emission (TSEE) dosimetric peak. Single crystals prepared in highly reducing conditions were treated in different atmospheres (reducing/oxidizing) and their...