Raman and X‐ray investigations of the incorporation of Ca2+ and Cd2+ in the ZrO2 structure

The formation of solid solution and ZrO₂ phase stabilization were investigated by Raman spectroscopy and X‐ray diffraction (XRD) in calcium‐containing and cadmium‐containing zirconium oxide samples heated at 1073 K in air. The adopted preparation procedure led to the incorporation of calcium and cadmium in solid solution into the zirconia structure. The solid solution favored the tetragonal and cubic zirconia phases at the expense of the thermodynamically stable monoclinic modification. Combined macro‐ and micro‐Raman spectroscopy disclosed that instead of forming a homogeneous phase t″, intermediate between the tetragonal t′ and the cubic phase, the tetragonal and cubic phases coexisted in the range 9.49–13.89 mol% for Ca and 11.88–17.23 mol% for Cd. At higher dopant contents the cubic form stabilized. The impurity content necessary to stabilize the high‐symmetry phases was defined. Copyright © 2007 John Wiley & Sons, Ltd.