Teitl: Mapping the Surface Phase Diagram of GaAs(001) using Droplet Epitaxy - data

Dyfyniad
Pereiro J, Jesson DE, Hannikainen K, et al. (2019). Mapping the Surface Phase Diagram of GaAs(001) using Droplet Epitaxy - data. Cardiff University. http://doi.org/10.17035/d.2019.0090902258


Hawliau Mynediad: Darperir Data dan drwydded Creative Commons Attribution (CC BY 4.0)
Dull Mynediad: I anfon cais i gael y data hwn, ebostiwch opendata@caerdydd.ac.uk

Manylion y Set Ddata
Cyhoeddwr: Cardiff University
Dyddiad (y flwyddyn) pryd y daeth y data ar gael i'r cyhoedd: 2019
Fformat y data: .dat, .csv
Meddalwedd ofynnol: UView and/or ImageJ
Amcangyfrif o gyfanswm maint storio'r set ddata: Llai nag 1 terabeit
Nifer y ffeiliau yn y set ddata: 15
DOI: 10.17035/d.2019.0090902258

Disgrifiad

Data, related to Figures in the relevant publication, are ...

Fig 1. Low Energy Electron Microscopy (LEEM) image representing a typical Droplet Epitaxy Phase Pattern around a Ga droplet under As flux. The contrast around the droplet is due to the change of the surface structure. We provide the raw data in .jpg format. This type of data can be opened with any image visualiser, such as Photos.
Fig. 2. (a) Steady-state Ga adatom chemical potential profile (in dimensionless units) versus distance to the droplet edge, as per Eq. 2 of the manuscript. We provide the data in .xlsx format, which can be opened using Excel.
(b) This figure is just a schematic and does not represent data. It shows the free energy of two general phases (alpha, beta) as a function of the Ga chemical potential, and indicates that the boundary of the phases occurs where the two free energies are equal. We provide the image in .png format that can be opened with any image visualiser, such as Photos.
Fig. 3. Three LEEM images showing the dynamic behaviour of the phase boundaries at different instants after opening and shutting off the As flux:  (a) before the surface is exposed to arsenic (b) after the Arsenic shutter is opened, and (c) after Arsenic shutter is closed. We provide the LEEM raw data in .jpg format. It can be opened with any image visualiser, such as Photos.
Fig. 4(a) The top panel shows instantaneous  low energy electron diffraction (LEED) of the surface at 8 microns from the droplet at different instants, as the boundaries move in and out when turning the As flux on and off.  The top panel shows all the diffraction patterns observed (associated to all surface structures). We provide the raw data in UView format. This type of data can be opened with UView or Image J. We attach a picture of the required image J import instructions. The bottom panel shows illustrative image interpreting the diffraction images from the top panel. The dots and lines represent diffraction contrast associated to the different reconstructions, in this order c(8x2), (6x6), (3x6) and (2x4). The image is not based on experimental data. The .PNG image that can be opened with any image visualiser, such as Photos.
(b) The figure shows experimental data representing the position of the phase boundaries I and II at different times after As shutter is opened and closed. We provide the boundary position vs time data in .xlsx format, which can be opened with Excel.
(c) Theoretical boundary trajectories of phase boundaries I and II after the As shutter is opened and closed. These are calculated solving the time-dependent reaction-diffusion equation. We provide the data in .xlsx format, which can be open with Excel.
Fig 5. Results produced from solving the time-dependent reaction-diffusion equation.  Here we plot instantaneous Ga adatom chemical potential profiles (in dimensionless units) versus distance to the droplet edge. (a) Represents the evolution after the arsenic shutter is opened and (b) the time evolution after arsenic the shutter is closed. We provide the data corresponding to the graphs in .xlsx format, which can be opened using Excel.  
Fig 6. (a)An image produced by combining dark -field LEEM images for all observed reconstructions,  in this order from the edge of the droplet c(8x2), (6x6),(3x6) and (2x4). The images are LEEM images. We provide raw data, in UView format. This type of data can be opened with UView or Image J. We attach a picture of the required image J import instructions.
(b)The bottom panel is an image modified from A. Ohtake, Surface Science Reports 63, 295 (2008). We have added 2 lines based on our results which represent the formation energy as a function of Ga chemical potential for (6x6) and (3x6) reconstructions. The position of these lines is based on our observation of the boundaries between surface phases at the growth temperature. PNG image that can be opened with any image visualiser, such as Photos.
Supplementary materials:
S1. Left: LEEM movie showing the dynamic behaviour of the phase boundaries when Arsenic shutter is opened and when the shutter is closed. Right: Low Energy Electron Diffraction image at a point at constant distance from the droplet. The diffraction illustrates all the different phases observed on the GaAs surface, in this order from the edge of the droplet c(8x2), (6x6),(3x6) and (2x4). We provide raw data in .jpg format for both the microscopy and diffraction videos. This type of data can be opened with any image visualiser, such as photos.
S2. Results produced from solving the time-dependent reaction-diffusion equation.  Here we show an animation presenting the evolving Ga chemical potential profiles versus distance to the droplet edge, when turning the As flux on and off. The horizontal dashed lines correspond to the chemical potential boundaries I and II. The vertical lines in motion correspond to the boundary positions in real space. We provide the MATLAB code that produces the simulation.

Research results based upon these data are published at https://doi.org/10.1103/PhysRevMaterials.3.124603



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