Checklist before the application to the PES beamtime
(1) The most important thing is to submit the beamtime proposal before the deadline!
- The safety and PI information are quite important to implement user’s projects.
- Note that all of the proposals are reviewed and scored by external reviewers.
- No proposal, no chance (except for the industrial service and collaboration projects.
- Clear description on why SR-XPS, and why not XAS, XRF, EPMA, mass spectrometry (SIMS, FABMS, etc.), or XPS using AlKα?
- The standalone XPS system is available in SUT-NANOTEC-SLRI BL5.1 XPS.
(2) The sample size must be large enough compared to the detection area.
- XPS samples should be more than 5x5 mm2 at least.
- XAS samples should be at least 5x5 mm2 larger than the beam size at the XPS position.
- Powders had better be attached as a pellet on carbon tape.
(3) Surface ex-situ impurities such as carbon and oxygen are sometimes negligible.
- Handle with care on the surface as clean as possible until loading the sample into the vacuum.
- In-situ ion sputtering is available at XPS and PES, and PES has a sample heater.
(4) The sample surface needs to be conductive.
- Surface must be conductive by doping or coating.
- Charging effect might be reduced at lower photon flux, but with poorer S/N.
(5) The probing target is whether surface or bulk.
- A depth profile is required to get into the bulk elements by the ion sputtering method.
- To do with ion sputtering, it is necessary to get more beamtime.
(6) The concentration of target elements in the surface or bulk.
- 1at% on the surface is a detection limit in the low photon energy (BE < 100 eV).
- To analyze the chemical states, 10% of element concentration is at least required.
(7) The binding energy of core levels and the kinetic energy of Auger peaks.
- Non-overlapped spectral profile within the photon energy range (PE < 1000 eV) without sample charging condition.
- The binding energy calibration is always required on the standard peaks or samples due to the instability of instruments.
- The literature survey reported previously on samples by XPS may give us great help to proceed with the experiment.
(8) The chemical analysis by XPS or XAS in the total electron yield mode.
- The standard samples are required to get information on chemical shifts.
- XAS might be a time-consuming experiment due to the slow undulator gap changing speed.
Estimated time for the experiment
For the ARPES end station
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Silver epoxy is cured at 100 C for 1.5 hours.
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The first sample set can be pumped down to the analysis chamber within 1.5 hours. The following sample set can be pumped during the measurements.
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Sample alignment and system setup take 40 minutes before the measurements of the new sample.
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The training of users takes 1-2 hours.
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Sample heating in-situ takes 2 hour to outgas (600 C at max).
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Sample cooling in-situ takes 6 hours in the range 300-100 K and takes 1 hour below 100-8 K.
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One ARPES spectrum takes about 40 min for band mapping.
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Sample holder changing takes 30 min,
For the XPS end station
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Sample preparation takes 10 minutes per sample for a pellet from powder.
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The first sample set can be pumped down to the analysis chamber within 2 hours. The following sample set can be pumped during the measurements.
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Sample alignment and system setup take 40 minutes before the measurements of the new sample set.
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The training of users takes 1-2 hours.
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The measurement of a sample typically takes about
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1 hour for XPS on survey(1 scan), C1s(3 scan), O1s(3 scan), In3d(3 scan), Sn3d(3 scan) at G#2, 600 eV
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20 minutes for UPS on survey(1 scan), cutoff(2 scan), VB(2 scan)
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1 hour for NEXAFS on C K edge (1 scan, non-tapering mode)
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For the PEEM end station
1. Experimental setup time
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Loading sample and vacuum pumping time: 2 hrs.
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Transferring sample and initial setup/alignment of the microscope: 1 hr.
2. Experimental time consumption per sample (depending on the type of measurement)
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Normal practice
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NEXAFS imaging: 0.5 – 1.5 hrs. /scan/element/location
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Micro-XPS / Dispersive-XPS: 0.5 hr. /scan/location
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LEED-IV: 0.5 hrs. /scan/location
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XPS imaging / ARPES: up to 2.0 hrs. /scan/element/location
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Work function mapping: 0.5 – 1.5 hrs. /scan/element/location
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Heating rate: approx. 100 degrees Celsius in 1 hr. (from up to 600 degrees Celsius)
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Heating rate: approx. 50 degrees Celsius in 1 hr. (from 600 to 1000 degrees Celsius)
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Special practice (example)
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Phase/structure transition observation: in-situ heating with LEEM time-lapse: 0.5 - 2 shifts per sample
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In-situ thin film deposition with real-time observation: 1 – 3 hrs. per deposition.
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For 3.2Ua PES
-In the "Sample" section
Add experimental plan and sample description
For 3.2Ub PEEM
-In the "Sample" section
Add experimental plan and sample description
