[labnetwork] Evaporation of Gadolinium

[Olona, Leonard E.]

Tony,

At a very high level… We would suggest the following.

  1.  Perform a through clean of the chamber and associated internals.   Scrape and scrub to bare metal.
  2.  Line the inside of the bell jar with UHV Foil.
  3.  Use a new Al2O3 Crucible.
  4.  Make a note on your cryo maintenance log that you are running the system with Gadolinium.
  5.  Perform a mechanical pump oil change prior to deposition and after.

Following these suggestions should lower the variables in your process.   I agree with you about the poor studies in regard to the presentation of this element.   I did see some papers where folks are using MBE for deposition.   I wonder how that maintenance campaign is performed!   Cant be any worse than cleaning up a HgCdTe system!!!

Good luck.

-Len

Leonard E. Olona
University Cleanroom Manager
University of Oklahoma
110 West Boyd Street Rm 550
Norman, Oklahoma  73019
D: +1- 405 325-4374
C: +1- 405 630-9068
F: +1- 405 325-7066



From: Tony L Olsen <tony.olsen at utah.edu<mailto:tony.olsen at utah.edu>>
Date: Tuesday, March 4, 2014 6:15 PM
To: "labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>" <labnetwork at mtl.mit.edu<mailto: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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