The effect of O vacancies upon the stability of phase structures and phase transformations in zirconia at low temperatures was studied by using an electrochemical technique. It was suggested that a decrease in O vacancy concentration decreased the stability of metastable tetragonal zirconia and promoted its transformation into the monoclinic phase.

X.Lu, K.Liang, S.Gu, Y.Zheng, H.Fang: Journal of Materials Science, 1997, 32[6], 6653-6