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problems with force curves/Nanoscope IIIA

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Luci posted on Thu, Sep 29 2011 12:15 PM

Please could anyone give us some advice on this problem with the Nanoscope IIIA.

The lab has been collecting force-volume data over the years without major problems with the force curves. In the last days, some problems have arisen when adjusting the laser on the cantilever.

AFM users have been unable to adjust the laser on long cantilevers as the spot does not hit the detector properly. They are able to align the laser on shorter cantilevers and when running force curves with this arrangement they observe severe interference on the curve as seen in the following image:

 

Seems that when the laser is aligned on the longer cantilever, it is somehow deviated from the right path and does not hit the detector properly.

 

There was a problem with the AFM head; the little spherical knob under the head went loose and detached from the base. It was carefully glued back. Is it a major problem that could cause some misalignment of the head not allowing a proper alignment of the laser on the cantilevers?

Thank you,

Luci

 

 

 

 

 

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Answered (Not Verified) replied on Thu, Sep 29 2011 3:44 PM

Hi Luci,

I cant see your images .... Not sure what you refer to when you say the "little spherical knob" went loose and you reglued it. Do you refer to one of the small metal balls that the cantilever cartridge rest upon? If you glued that in not properly seated you cantilever mount may indeed be at an angle thus deflecting your spot to a location off the photodetector.  Can you please specify?

Stefan

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Top 75 Contributor
13 Posts
Points 154
Luci replied on Thu, Sep 29 2011 4:17 PM

Stefan, thank you for your message. Unfortunately, there is some problem with my connection to the forum and I'm unable to post the images. I tried to copy directly from my url and also pasting it from word but did not work.

Is there any other way we can send the images?

Thank you,

Luci

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replied on Thu, Sep 29 2011 4:51 PM

Hi Luci,

here is a link on how to post images: http://nanoscaleworld.bruker-axs.com/nanoscaleworld/forums/t/526.aspx

I do understand that you can not adjust the laser properly and that you reglued a knob. Can you please indicated which knob you reglued and how?

Thanks, Stefan

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Top 75 Contributor
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Luci replied on Mon, Oct 3 2011 11:19 AM

Hello Stefan,

Thank you for the hints on how to edit the post.

Yes, the metal balls that support the cartridge were reglued.

This is the image obtained with the laser hitting the shorter cantelever:

There are interference on the curve. Another picture shows the position of the laser on the cantilever and the path to the detector.

If you could advise if it is necessary to send the head to be repaired we would be grateful.

Luci

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replied on Mon, Oct 3 2011 3:47 PM

Hi Lucy,

It looks like you your sample is very adhesive and you do see some laser interference. Did you try a coated silicon tip to see if the interference is still there, e.g. a TESPA or similar.

If you cleaned the supports before you reglued the balls and the balls are in the same location, i.e. not sticking out further, it should be OK. This is however difficult to say from here. It can not hurt to contact Bruker tech support and ask them as they may have dealt with that issue before.

Stefan

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Top 75 Contributor
13 Posts
Points 154
Luci replied on Tue, Oct 4 2011 3:17 PM

Stefan,

Thank you for your help.

Luci

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