ABSTRACT
It is demonstrated that various phases of ZrO2 can be characterised using 91Zr NMR spectroscopy by their distinctive nuclear quadrupolar powder patterns. We display the 91Zr NMR line shapes of the cubic, monoclinic and tetragonal phases of ZrO2 and show how zirconium spectra can describe these and the other phases exhibited by magnesia-partially-stabilised zirconia (MgPSZ) during the course of heat treatment subsequent to the preparation of the as-fired material. Specifically, we have observed the growth and ordering of the tetragonal precipitates on isothermal aging at 1400 °C, the partial transformation of the cubic to the δ-phase (Mg2Zr5O12) on annealing at 1100 °C, and the transformation of the tetragonal phase into the orthorhombic phase after cooling to 77 K, followed by the reverse transformation on warming to 600°C.
