Effect of CuO additives on the reversibility of zirconia crystalline phasetransitions

We have studied the influence of the differents atmospheres on the sinterin g of CuO-doped-zirconia ceramics. After an annealing treatment in a reducin g atmosphere, we have found nanoparticles of metallic copper in triple poin ts and in the grains of the sintered zirconia. Furthermore, the influence o f the intergranular Y2Cu2O5 phase on the tetragonal to monoclinic phase tra nsition and the crystalline structure of zirconia is discussed with respect to results obtained from X-ray diffraction, differential thermal analysis, Raman spectroscopy and High Resolution Transmission Electron Microscopy. ( C) 1999 Kluwer Academic Publishers.