Data for Master Thesis "Ion Beam Shaping of Catalytic Nanoparticles"

This repository contains the data used in the master thesis “Ion Beam Shaping of Catalytic Nanoparticles”, which is part of the CatIons FFG project. 

Context and methodology

• AuCu nanoparticles can be used to catalyze chemical reactions, such as the water gas shift reaction, which converts CO and steam to CO₂ and H₂. Their catalytic properties depend on the size and shape of nanoparticles. The goal was to use ion beam irradiation to shape spherical particles into a shape with different catalytic properties
• The irradiation of 10 nm AuCu particles was simulated using the software SDTrimSP-3D.
• AuCu nanoparticles on glassy carbon substrates were irradiated and measured using AFM before and after irradiation.

Technical details

·       The folder “AFM” contains atomic force microscopy images of various samples that consist of a glassy carbon substrate with Au, Cu, or AuCu nanoparticles drop cast onto the surface. The images are organized into folders by sample. Their status (sputter cleaned/freshly drop cast/irradiated) is indicated in the file names of the images. The AFM images are .ibw files, which can be opened and processed using the free software Gwyddion (Version 2.69 was used in the course of this thesis). Additionally, there are .jpg files with screenshots showing the positioning of the AFM cantilever on the sample surface.

·       The folder "SDTrimSP-3D" contains various folders, which each contain a simulation. The files are compatible with version 2.50 (incompatible with earlier versions!) To run a simulation with SDTrimSP-3D, its folder needs to be added to the “case” folder in the SDTrimSP-3D directory. The necessary input files to start a simulation are always named “tri.inp” (general simulation parameters), “fig.inp” (target geometry and composition) and “stop_run.inp” (0 or 1, depending on if the simulation should be stopped during a run)

·       The output files created during the simulations are in the same folders.

-time_run.dat tracks the progress of the simulations

-Target_cut_00_3D.dat and Target_cut_90_3D.dat provide information on the coordinates and composition of a cross section of the target at each fluence step

-surf_cut_00_3D.dat and surf_cut_90_3D.dat have a similar format, but only include the surface profile of the cross section

-an amira.iv file is created for every single fluence step (number of outputs defined in tri.inp). Each one contains a list of voxels representing the 3D shape of the target.

·       The folder Python contains the scripts used to plot the 2D and 3D output files, as well as Text_to_FigInput.py, which generates a fig.inp file for a target consisting only of spheres from spheres.txt. The scripts are modified versions of scripts originally created by Paul Szabo

·       The folder SW_sphere_Au1Cu1 also contains analysis on the shape of the particle at fluence 0.0, 0.5 and 1.0

·       More information in SDTrimSP-3D Documentation

·       The folder “Sputter Source” contains information on the profile of the ion beam of the sputter gun. The current for the 2D profiles was measured using an M3 screw and washer as a faraday cup. The 1D profiles use the straight bottom edge of a sample holder. The current was measured using a picoamperemeter. The sample holder was moved manually. The measured currents are recorded in .csv files and plotted with plot2D.py and plot3D.py