Êtes-vous un étudiant de l'EPFL à la recherche d'un projet de semestre?
Travaillez avec nous sur des projets en science des données et en visualisation, et déployez votre projet sous forme d'application sur Graph Search.
Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to study the porous and non-porous alpha-tricalcium phosphate (alpha-Ca-3(PO4)(2), alpha-TCP) prepared through a sintering procedure at 1200-1400 degrees C of beta-tricalcium phosphate (beta-Ca-3(PO4)(2), beta-TCP). The interpretation of experimental and calculated X-ray and electron diffraction patterns showed that the final product at 1400 degrees C was primarily alpha-TCP but roughly 3.0-8.0 wt.% of the starting beta-TCP phase and up to 8.0 wt.% of CaO were in the final product. TEM images and electron diffraction patterns showed that the CaO phase - formed by decomposition of TCP - exists as micron-sized areas of various oriented nanocrystals embedded into the bulk alpha-TCP material and also as self-standing spherulite particles of a few microns in size. Surprisingly, formation of CaO from TCP decomposition occurred at temperatures below those predicted from the phase diagram of the CaO-P2O5 system. (C) 2009 Elsevier Ltd. All rights reserved.
Antonia Neels, Marianne Liebi, Tiberiu Totu