Microstructure of pulsed-laser deposited PZT on polished and annealed MGO substrates

Thin films of Lead-Zirconate-Titanate (PZT) have been grown by pulsed-laser-deposition (PLD) onto polished MgO substrates both with and without pre-annealing. The surface morphology of polished MgO substrates, which are widely used for deposition, is examined by AFM. Commercially available, mechanically-polished substrates are shown to be microscopically very rough and seem unlikely to present a surface suitable for the growth of the highest quality thin films. Annealed MgO substrates, on the other hand, comprise atomically flat terraces. The use of annealed substrates is found to enhance considerably the crystalline quality of PZT films deposited thereon