Formation of metastable solid solution in the ZrO 2-rich part of the system ZrO 2Al 2O 3

Abstract

A metastable ZrO 2Al 2O 3 solid solution was successully synthesized by coprecipitation of hydroxides over the range 0 to 25 mol% Al 2O 3. Combined evidence from XRD and Raman spectroscopy shows the presence of two forms t′ ( c/ a ⪢ 1) and t″ ( c/ a = 1) of the ZrO 2 tetragonal structure. 27Al MAS NMR analysis shows the existence of the three sites AlO 4, AlO 5 and AlO 6 in the whole range of the solid solution. Results of this study provide further insight into the nature of the metastable solid solution.