Title : Oxide Substrate Termination and 2D growth of perovskite magnetic oxide ultra thin films
Single-site atomic termination of oxide single crystalline substrates are becoming highly essential due to the growing popularity and demands of Reflection High Energy Electron Diffraction (RHEED) assisted 2D epitaxial layer-by-layer growth of thin film heterostructures and the associated physics at their interfaces. Understanding the complex interactions in perovskite oxide heterostructures, both electronic and magnetic, can be realized only when the growth of such materials is fully under control. In this regard, we have achieved single-site atomic termination in SrTiO3 (001) and (111). However, substrates like LSAT (001) known to pose hurdle in achieving an atomically smooth single-site termination at the surface, hindering a controlled growth process. We have performed study of the evolution of step-terraces by studying the various influential annealing parameters which are seldom end-to-end. Further, growth of 2D epitaxial layer-by-layer growth of various perovskite magnetic oxides up to unit-cell thickness level are demonstrated using pulsed laser deposition (PLD) technique. We have extensively investigated growth of variety of magnetic materials such as doped manganites and ruthenates on atomically terminated substrates. Different influential deposition condition parameters of growth, such as, growth temperature, pressure, laser beam conditions etc. are studied to understand the growth modes of the thin film. RHEED spots and the intensity oscillations of the specular beam are monitored to observe the growth mode. Important findings such as X-ray diffraction, reflectivity measurements and results of atomic force microscope images will be further discussed on supporting the optimal growth conditions of thin film systems. Magnetic measurements of such samples along with Curie temperature as a function of thickness will also be dealt in detail.
What will audience learn from your presentation
• Knowledge of influential parameters in deciding the step-terraces of the substrates and the deposition conditions are crucial but time-consuming process. My talk will provide an overall clear picture of the phase-space involved.
• Understanding of the complex PLD growth of thin film would provide the audience a complete practical knowledge before-hand while working on a new material.
• I will cover how the control over the growth can help one to control all the associated electrical and magnetic characterization achieved with quality close to its single-crystal bulk counterparts.