The recent demonstration of the epitactic growth of YBa2Cu3O7-x (YBCO) onto (100) MgO passivated by a layer of the inverse spinel Mg2TiO4, combined with the large number of possible reaction products of” widely differing structure (normal spinel (Ti3+), inverse spinel, pseudo-brookite, perovskite) make the MgO-TiO2 system one of the more interesting, and complex, currently under examination.
Over the last few years, Hesse, Bethge and co-workers (see 1 for refs), have applied various microscopal techniques to the study of e-beam evaporated TiO2 onto MgO. The present paper extends this investigation to pulsed-laser deposited (PLD) TiO2 onto MgO. Unlike almost all previous studies of PLD films, pre-characterized “TEM-ready” substrates are used, a technique pioneered by Norton et al, thereby circumventing the possibility of affecting the film morphology during the thinning process. This technique also allows the imaging in the TEM of identical areas both before and after deposition.