From cbellew at snf.stanford.edu  Thu Apr  8 12:47:45 2004
From: cbellew at snf.stanford.edu (Colby Bellew)
Date: Thu, 08 Apr 2004 12:47:45 -0700
Subject: Recent problems with AFM tips
Message-ID: <4075AC61.7040402@snf.stanford.edu>

Mahnaz informed me that a few users had reported problems with the new 
afm tips that the stockroom recently received from Veeco.  I checked 
them out to see if there were any obvious problems with the tips.  
Although they look slightly different, I was unable to find any 
fundamental problem with them.  They still have the line that runs along 
the long axis from the middle of the silicon block.  The cantilever is 
at the end of this line. 

I loaded one of the new tips into the afm and I did have some difficulty 
finding the cantilever, but it was not the fault of the tip.  The 
photodetector was misadjusted so badly that even when the laser was on 
the cantilever, there was no sum signal on the computer screen.  There 
was also no red dot on the small window on the microscope head.  I 
eventually got it back so that I was able to get everything aligned and 
I did a scan without any problem.

The tip I used was in a package that was marked "BAD TIPS" that was next 
to the microscope.  I checked out all of these tips under an optical 
microscope and only one of them was broken; the other four were fine.  I 
removed the bad tip.  I'm not sure who bought these tips, but if you 
paid for them, you should go reclaim them.  If you didn't pay for them 
because you thought they were bad, you should go pay for them.

Smooth operation of the microscope depends on each user running the 
machine correctly.  Therefore, if a user is unable to adjust the laser, 
photodetector or optical camera successfully, then they need to either 
find an experienced user who can help them fix the problem immediately 
or they need to right it up as a problem on Coral.  Otherwise, the next 
user will not know that things may be grossly misadjusted.

Good luck and happy imaging,

Colby

-- 
---------------------------------
Colby L. Bellew, Ph.D.
Stanford Nanofabrication Facility
CIS Room 143
Stanford, CA 94305-4070
(650) 725-4702
cbellew at snf.stanford.edu
---------------------------------