Quantitative determination of energy enhanced interlayer transport in pulsed laser deposition of SrTiO₃

We show that the analysis of single-shot surface x-ray diffraction transients in terms of time-dependent coverages allows quantitative determination of interlayer transport in pulsed-laser deposition of SrTiO ₃. The fast interlayer transport during and immediately after the arrival of the laser plume and before crystallization represents the dominant mechanism for redistribution of the deposited material that is completed on a μs-range or faster time scale. Following crystallization interlayer transport is more than four orders of magnitude slower because it is driven only by sluggish thermally activated processes, which represent a small fraction of total interlayer transport that decreases with increasing laser repetition rate. The analysis of growth kinetics shows that it is fast interlayer transport driven by hyperthermal energy species and not thermal annealing that governs layer completion that determines the growth mode and the formation of atomically sharp interfaces in pulsed-laser deposition of epitaxial oxide films and similar energy-enhanced growth processes.