J. Phys. IV France 08 (1998) Pr5-85-Pr5-89
Cell parameters refinements showing an influence of the chemical nature of the grain surface on the crystalline characteristics of fine grained powdersP. Sarrazin1, 2, F. Bernard2, G. Calvarin3, J.C. Niepce2 and B. Thierry1
1 Laboratoire des Matériaux Avancés Céramiques, Université de Valenciennes, CRITT "Céramiques Fines Techniques", Z.I. Champ de l'Abbesse, 59600 Maubeuge, France
2 Laboratoire de Réactivité des Solides, UMR 5613 du CNRS, BP. 400, 21011 Dijon, France
3 Laboratoire de Chimie-Physique du Solide, URA 453 du CNRS, École Centrale de Paris, 92295 Chatenay-Malabry, France
The evolution of the cristalline state of fine grained BaTiO3 powders has been investigated by X-ray diffraction during desorption - adsorption cycles in order to study the effect of the chemical nature of the surface of fine grains on their interna1 crystalline structure. A weak but significant increase in the cell parameter has been observed after adsorption of water on a nanometric BaTiO3 powder, showing that the physico-chemical interactions between the solid and the adsorbent are responsible for a tension state in the material. Similar evolution has been previously observed on nanometric MgO powders ; this phenomenon can be generalized to all kind of fine grained materials.
© EDP Sciences 1998