J. Phys. IV France 7 (1997) C2-1241-C2-1242
XAS Study of CuAl2O4 Ceramic SystemV.R. Mastelaro and P.I. Paulin Filho
Departamento de Engenharia de Materiais, UFSCar, São Carlos, S. P. Brazil
XAS technique was used to study changes around Cu atom in the CuAl2O4-Al2O3 system, induced by composition variations. The results showed that for compositions with 30 and 43% of CuO, the Cu atoms presents the same surroundmg of Cu in the CuO oxide (NCu-O=4, RCu-O=1.96 Å). Samples with 20% (doped or undoped) showed significative changes in the Cu nearest neighbors number (NCu-O=3) and in the mean bond length (RCu-O-1.93 Å). The qualitative analysis of the edge region showed that for the 20% of CuO sample, some Cu atoms changes from Cu+2 to Cu+1. This change was more pronounced for the CuO 20% undoped sample.
© EDP Sciences 1997