[labnetwork] question about Liner for Ni Ebeam Evaporation

[Yakimov, Michael]

Nickel expands on crystallizing, like Al - so if it wets crucible walls, crucible will crack.
Slow cooldown, effectively re-melting and re-crystalizing layers at crucuble sidewalls helps a bit, but that's about it.

The good news is that you can still run from the center of cracked crucible if it doesn't expand way out. Ni evaporates not too far above melting point - so walls can stay below melting point and metal is still contained. Some carbon contamination... I didn't look at it myself, but  pretty likely anyway.

Just my2 cents

Mike




_______________________________________________

Michael Yakimov

Research scientist

Department  of Nanoscale Science and Engineering

University at Albany - State University of NY



253 Fuller rd.

Albany NY 12203



Phone: 518-437-8609 lab

e-mail: myakimov at albany.edu

________________________________
From: labnetwork <labnetwork-bounces at mtl.mit.edu> on behalf of Shawn Wagoner <swagone at gmu.edu>
Sent: Wednesday, December 4, 2024 9:01 AM
To: shokoofe haghighi <shokoofe_haghighi at yahoo.com>; labnetwork at mtl.mit.edu <labnetwork at mtl.mit.edu>
Subject: Re: [labnetwork] question about Liner for Ni Ebeam Evaporation


For e-beam of Ni you should try a “starter source”.  At least that is the term I learned long ago.  It is a solid piece of Ni in the shape of the pocket of your gun.  No additional liner is used.  As you evaporate the Ni and create a small hole in the top of the source you simply add Ni pellets.  It last a long time this way.  Most of the suppliers should be able to supply this to you.  I used to buy them from Kamis.



Shawn



From: labnetwork <labnetwork-bounces at mtl.mit.edu> On Behalf Of shokoofe haghighi
Sent: Wednesday, December 4, 2024 4:35 AM
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] question about Liner for Ni Ebeam Evaporation



External Message: Use Caution



Hi, hope you are having good days,



this is Haghighi, working on metallization by a PVD, using thermal and Ebeam evaporation.



I have some issues choosing the right liner for Ni Ebeam evaporating, hope you find time to guide me through it.

We have tested graphite, glassy carbon coated graphite, Al2O3, Mo, W and Cu liners so far.

    Graphite liner just broke after first run from the border line of Ni surface. Glassy carbon coated graphite was more or less the same,

    Al2O3 endured for 4-5 runs before breaking but there were cracks on it,

    Mo liner totally melted and some kind of alloy was produced,

    W and Cu endured but their internal walls were some how melted and we can't be sure about pureness of evaporated Ni and final produced thin films.



do you have any other suggestions?





high voltage: 6.1 KV

emission current: 3 - 5 A





Thanks for your time and attention in advance, I hope you kindly find time and consider replying me,



Dr. Haghighi


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