Electrical measurements and SAM V

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Stephen Minne replied on Wed, Nov 17 2010 5:26 PM

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Tim,

#1 is correct. Remember, NEVER put a high voltage input into the SAMV

#2
The best way to do this is not to use the SAMV, but is from within the NSV. To do it in the NSV you will need to separate the AC and DC, applying one to the tip and the other to the sample.

In general, the performance of PFM will be degraded if you go through the SAMV. This is simply because adding in more cables and electronic elements degrades the integrity of small signals that must be detected.

In any case, you will not be able to apply the AC signal through the SAMV if you want to use the lockin internal to the NSV (again, also recommended), if you must apply the AC external you will also have to use a your own external lockin.

The DC and ramp capabilities in the NSV should meet your requirements, if not, you can apply the DC externally using the SAMV, but again, for best performance we recommend using the included features.

Best,
Steve

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T replied on Thu, Nov 18 2010 3:07 AM

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Hi Steve,

thanks very much for your replies. And thanks for the typo correction I was a little confused about PFT! I will try some things out and get back to you.

Tim

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T replied on Fri, Nov 19 2010 10:10 AM

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Hello again,

I have a follow on question regarding signal routing. In surface potential measurements when I open the Generic Lockin I cannot see the drive routing destination. I would like to be able to change between applying the AC signal through the sample and tip as well as extracting the signal through the SAM V or front panel if possible.

How would this be possible?

Thanks

Tim 

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replied on Fri, Nov 19 2010 11:44 AM

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Hi Tim,

Older software versions had indeed the option to switch the routing of the ac-signal from tip to sample. Unfortunately, this caused a lot of confusion in the field so it was decided to fix the routing the way it is currently implemented. That is why you do not get an option here.

Now, I am sure there is some way to use the SAM V to reroute the signals using some creativity. That is after all what the SAM V is all about. I have however not tried that as I never had the need so I can not suggest an exact on how to do that right now. The extraction of signals should be, however, straightforward. Can you explain what the issue is and what signals you have trouble getting?

Stefan

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T replied on Mon, Nov 22 2010 3:37 AM

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Hello Stefan,

the problem is related to my other post about using the heater and simultaneously doing electrical measurements.

I think I am right in saying that the tip holder with tip heater cannot also deliver electical signals to the tip? That certainly seems to be the case with my cantilever holder.

So my issue is that I am trying to discover the best way of combining use of the heater stage and tip holder whilst still being able to carry out all of the electical modes of operation.

I would be grateful for any advice on this

Thank you

Tim

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replied on Mon, Nov 22 2010 4:09 PM

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Hi Tim,

I think think you are correct with regards to having to modify a cantilever holder to allow for both of your measurements. I have performed both but not simultaneously. I'll check with some of my collegues and will get back to you.

Stefan