Fig. 3.

Oxygen-isotope-sensitive ion spectroscopy measurements performed on the SrTiO₃(110)-reconstructed surfaces. a LEIS spectra (He⁺ with 1000 eV primary energy) measured on (4 × 1)- (black), and (2 × 5)-reconstructed (red) SrTiO₃(110) surfaces, respectively. Results from as-prepared and ¹⁸O-exchanged samples are displayed with full and open symbols, respectively. Each spectrum is normalized to the total O signal. The uncertainty (standard error) on the fractional ¹⁸O signals reported in the table is 0.4% for both surfaces. b ToF-SIMS ¹⁸O isotope exchange depth profiles measured on (4 × 1)- (black), and (2 × 5)-reconstructed (red) SrTiO₃(110) surfaces of the same crystal. Here, open and full symbols correspond to two separate measurements on different spots on each half of the bi-crystal