Crystal Cleanning

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Crystal Cleanning

Postby jlopez » Mon Nov 09, 2009 5:50 pm

Many times I have had to clean a single crystal that I am not familiar with and have found that every person that works with that type of crystals uses a different "recipe" to get the sample clean. I thought that this would be a good place to make a collection of the recipes and then they would be accessible to everybody when we need to have an idea of the cleaning procedure for a sample that we are not used to. Said that, the question for everybody in the community would be, what sample you use and which way do you clean it?
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Crystal Cleanning: Au(111)

Postby jorgeab2 » Wed Nov 11, 2009 1:41 pm

For cleaning a Au(111) single crystal. Bombard with Ar+ with a current of ~2 uAmps and a voltage of 500V for about 30mins. Then anneal to ~620C for 5 mins followed by 30 mins at ~420C. Repeat the same until the sample is clean. I check that is clean by getting the herring-bone reconstruction by STM.
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Crystal Cleanning: Cu(111)

Postby anibalbosco » Mon Nov 16, 2009 10:37 am

Cu(111):
Bombard with Ar+, 2uAmp, 1kV, 30mins. Anneal to 25 mV (type k thermocouple) for 30mins to flatten the bombarded surface. Check cleanness by Auger. If not completely clean,repeat cycle.
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Crystal Cleanning: Pd(111)

Postby jorgeab2 » Thu Jun 10, 2010 1:02 pm

Pd(111)
1.Ar+ sputtering 1kV, 4uAmp, 30mins.
2.Anneal to 1000K for 5 mins.
3.Anneal between 740K and 875K while dosing O2 on the surface (4E-8Torr seems a reasonable pressure) for 30 mins moving in this Temp range during this time.
4.Flash to 1000K and let it cool down to 550K under an O2 pressure of about 4E-8Torr . Repeat this step a few times (5 might be good).
5.Check for cleanness with a technique you have available (O2 TPD, Auger, etc.). You might have to repeat steps 3 and 4 a few times until the sample is clean.
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