[labnetwork] advice on work safety when sputtering Osmium

[Gerhard Ulbricht]

Dear all,

I'm looking for advice on Osmium (Os) sputter deposition. We are 
interested in its superconducting behavior, and I would like to ask you 
if anyone has experience with Os sputtering and especially with the 
required safety procedures.

More details:
  - We intend to sputter Os from a bulk 2" Os sputter target in a UHV 
system.
  - The main danger with Os is its oxide (OsO4) which is volatile and 
highly toxic.
  - It is known that Os powder at room temperature oxidizes on its own 
to OsO4, but bulk Os has to be heated above 400 C.

The sputter process will coat both sample and the inside of the sputter 
system with thin Os films. Save sample handling is no issue, but what 
precautions would be advisable for the sputter system itself? My main 
worry is system maintenance: That's the only time the Os inside will 
come into contact with Oxygen. Will the thin film inside react like Os 
powder and form OsO4 even at room temperature? Or should we expect the 
oxidization to be minimal at room temperature?

I appreciate any advice you can give,

Gerhard Ulbricht
University of California Santa Barbara
Santa Barbara CA 93106
ulbricht at physics.ucsb.edu