A solution chemistry approach to epitaxial growth and stabilisation of Bi2Ti2O7 films

Abstract

Single crystalline pyrochlore Bi₂Ti₂O₇ films have been grown in three different orientations on yttria-stabilised zirconia at temperatures as low as 600 °C, by using a simple wet chemistry method based on the spin-coating technique. Contrary to free-standing powders and polycrystalline films, epitaxial single crystalline Bi₂Ti₂O₇ is stable relative to other bismuth titanate compounds at temperatures up to 900 °C. A study of core X-ray photoelectron spectra shows Bi₂Ti₂O₇ films contain an oxygen deficiency whose concentration depends on the annealing temperature. Based on low-energy ion scattering spectroscopy, it was determined that crystalline surfaces terminate in BiO_x-like structures.