[labnetwork] Evaporation of Gadolinium

[Luciani, Vincent]

Good Morning Tony,

We use a disposable "chimney" inside or e-beam evaporator to contain the Gd.

More:
Here at CNST we have many users that build test structures for use at NCNR (NIST Center for Neutron Research).  Gd is very popular for its neutron absorption qualities.  We are incrementally improving our technique and still need to improve it further.  For now we evaporate Gd in our e-beam system.  We built a substrate holder  that stand on stilts, strategically positioned to avoid the obstacles and rest on the baseplate.  The stilts also provide a skeleton that we wrap with foil.  A fresh piece for each deposition.  The foil chimney is capped with the substrate holder.  We performed timed depositions at first but since this works for us we are adding a crystal monitor inside the chimney.  I don't have any pictures handy but can get a couple next time we use it.

Gd flakes and particles are very flammable in air (maybe toxic) so we carefully fold up the Gd coated foil and package it for pick up.  We worked with our Safety folks and waste removal company for the right way to package it.  I can get you details of that if you like.

Vince


Vincent K. Luciani
NanoFab Manager
Center for Nanoscale Science and Technology<http://www.cnst.nist.gov/>
National Institute of Standards and Technology
100 Bureau Drive, MS 6201
Gaithersburg, MD 20899-6200 USA
+1-301-975-2886






From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Tony L Olsen
Sent: Tuesday, March 04, 2014 7:15 PM
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] Evaporation of Gadolinium

All

We have received a request to evaporate gadolinium.  The request presents several handling and safety concerns, including contamination of the process chamber and vacuum pump.  The toxic nature of gadolinium seems to be poorly studied, resulting in some debate.  We are uncertain if there is an appropriate approach to successfully and safely allow this material in an e-beam system.  Does anyone have any experience, comments, or suggestions?

Thanks,
tonyO


Tony Olsen
Nanofab Cleanroom Supervisor/Process Engineer
University of Utah
36 S Wasatch Dr, Suite 2500 SMBB
Salt Lake City,  UT  84112
801-587-0651 office
801-587-3077 fax
www.nanofab.utah.edu<http://www.nanofab.utah.edu/>


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