Study of the behavior of zirconia powders doped with aliovalent ions

Abstract

Zirconia is one of the three bio-ceramic materials, along with alumina and hydroxyapatite, used as components for prosthesis for restoring mobility and well-being of a growing number of patients. In this study we try to understand the behavior of the phases and the lattice strain inside the zirconia doped powders to track new information to enhance the durability of the material over time. The phase transformations of zirconia show a complex dependence on temperature, stress and environment. Also inserting within the lattice of this ions of different sizes and charge can modify the host’s crystalline phase. In this thesis has been used zirconia powders doped with trivalent and pentavalent ions. Zirconia doped materials were prepared by soft chemistry with thermal treatments at 1000°C. Samples were characterized by X-ray powders diffraction and Raman spectroscopy. The lattice of the zirconia has been doped with Y2O3, Ta2O5 and with a mixture of Ta2O5-Y2O3. Using different ranges of dopant concentration percentage is possible to monitor the phase change of the host lattice. This work has allowed us to identify certain crystalline phases at room temperature which are stable after thermal treatments. Through the results of the analysis we realized that the zirconia doped with pentavalent ions open new possibilities in the field of materials science due to its interesting properties.