[en] 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 1x10¹⁷ ions/cm² was completed at room temperature. After annealing at 1100 deg. 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(Ti_xZr_1-x)₂O₇, with a congruent with 10.24±0.05 Aa. 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