Real-time X-ray Scattering Data and Kinetic Monte Carlo Simulation Data for Homoepitaxy of Strontium-Titanate by Pulsed-Laser Deposition.

This repository contains X-ray Scattering Data, Kinetic Monte Carlo (kMC) Simulation Data, and Meta files. X-ray data was collected at the National Synchrotron Light Source 2 (NSLS-II) at the ISR beamline in August 2018. The sample was 64 layers of Strontium Titanate (STO) deposited on STO by Pulsed-Laser Deposition. The sample was grown at 600 C under an Oxygen pressure of 2 mTorr. The dwell time between pulses was 6 seconds and the pulses per layer was 18, or 0.055 coverage per pulse. See Meta file for further details. The two data files are a time-series specular intensity and a time-series circular-averaged diffuse scattering. A simple python jupyter notebook is included to load and display the data. Kinetic Monte Carlo Simulations of Layer-by-Layer growth by PLD were done using a Solid-on-Solid Bond-Counting model on a simple Cubic Lattice. 60 layers were simulated. Parameters were chosen to closely match the experimental conditions above: The substrate temperature was set to 600 C, the dwell time to 6 seconds, the pulse width to 1e-10 seconds, and pulses per layer was 20. The surface diffusion rate was set 407.84 inverse seconds from an activation energy of 1.8 eV and a prefactor of 1e13 inverse seconds. An addition barrier for detachment from islands was 0.3 eV. Edge and Corner diffusion barriers were set to 10.0 eV, effectively shutting these processes off. An Ehrlich-Schwoebel Barrier was set to 0.0 eV, leading to no additional barrier for downhill or uphill diffusion. Three data files are included: An images file, in .hdf5 format, contains a time-series of real space images of the surface. Two .npy files contain simulated anti-Bragg Specular Intensity and Circular-Averaged Diffuse Scattering. Two Jupyter notebook files are included to load and display this data. See Meta file for more details. The kMC code can be found at https://github.com/jeffreyulbrandt/Kinetic-Monte-Carlo