The layered structure of oxides, like the high-T, cuprates, has been topic of research for some years now. The possibility to control thin film deposition on an atomic level has made fabrication of artificial structures and junctions accessible by depositing atomic layers or molecular blocks sequentially. Perfectly smooth substrate surfaces are hereby a prerequisite.
Using Pulsed Laser Deposition (PLD), different perovskite oxide materials have been deposited on SrTiO3 substrates. With in situ high pressure Reflection High Energy Electron Diffraction we studied growth at different temperatures and oxygen pressures. Ex situ XRD and AFM have been used to study the morphology after deposition.
Here we applied a new approach in obtaining layer-by-layer growth implied by the way of depositing the material, almost regardless of the deposition conditions. By alternating intervals of high supersaturation depositing one unit cell layer with intervals of lower supersaturation, one is able to force a layer-by-layer growth mode, which is in principle only feasible with PLD. We applied this technique to fabricate the layered infinite structure (Ba,Sr,Ca)CuO2 with artificial layered modulation, which have been characterized by XRD and AFM.