Nanodomains of pyrochlore formed by Ti ion implantation in yttria-stabilized zirconia

Abstract

The microstructural evolution of a single crystal of yttria-stabilized zirconia (YSZ) implanted with Ti has been studied by cross-sectional transmission electron microscopy (TEM). The implantation of 180 keV Ti ions to a dose of 1×1017ions/cm2 was completed at room temperature. After annealing at 1100°C in an Ar atmosphere for 2 h, a phase transition from the fluorite structure of ZrO2 to an isometric pyrochlore structure-type, A2B2O7, occurred due to cation ordering. High-resolution TEM revealed nanodomains of pyrochlore, Y2(TixZr1-x)2O7, with a≅10.24±0.05Å. The nanodomains of the pyrochlore phase, embedded within the YSZ fluorite substrate, occurred in a depth range from 45 to 105 nm below the surface, which corresponds to Ti concentrations from ∼10 to ∼15 at.%. The nanoscale pyrochlore precipitates and the YSZ matrix have a completely coherent orientation. © 2002 American Institute of Physics.