Actually, i wouldn't recommend that either 😊

My experience with the Ta heaters is that they react with even the smallest 
amount of oxygen, and bottled N2 has more than enough to kill a Ta strip. The 
best result we had was with a H2/N2 mix, but that still failed (probably 
reaction with the sample).  Personally I think the only reliable way to use 
them is with a high vacuum system (turbo pump), and with relatively inert 
samples.

Ultimately you are better off getting a Pt strip instead.


Jools


From: [email protected] <[email protected]> On Behalf Of 
Mibeck, Blaise
Sent: torsdag 25. juli 2019 16.27
To: Payzant, Andrew <[email protected]>
Cc: [email protected]
Subject: Re: [EXTERNAL] Mounting Sample on High Temperature XRD Ribbon Heater

Thank you -- I will try nitrogen then!


________________________________
From: Payzant, Andrew <[email protected]<mailto:[email protected]>>
Sent: Thursday, July 25, 2019 9:08 AM
To: Mibeck, Blaise <[email protected]<mailto:[email protected]>>
Cc: [email protected]<mailto:[email protected]> 
<[email protected]<mailto:[email protected]>>
Subject: Re: [EXTERNAL] Mounting Sample on High Temperature XRD Ribbon Heater


STOP!!!



The tantalum foil should not be used for high temperature in air. Above a few 
hundred degrees Celsius it will oxidize rapidly and disintegrate.

I accidently learned this the hard way many years ago!  😉



Either use an inert atmosphere or vacuum. Or use a different heater ribbon, 
suitable for air atmosphere.



Andrew



*****************************************************



Dr. E. Andrew Payzant

Materials Engineering Group Leader

Neutron Scattering Division

Neutron Sciences Directorate



Mailing address:

Oak Ridge National Laboratory

Dr. E. Andrew Payzant

P.O. Box 2008

Bldg. 8600, MS 6475

Oak Ridge, TN 37831



cell: (865) 235-4981

email: [email protected]<mailto:[email protected]>

https://www.ornl.gov/staff-profile/e-andrew-payzant



******************************************************







From: <[email protected]<mailto:[email protected]>> on behalf 
of "Mibeck, Blaise" <[email protected]<mailto:[email protected]>>
Reply-To: "Mibeck, Blaise" <[email protected]<mailto:[email protected]>>
Date: Thursday, July 25, 2019 at 10:03 AM
To: Rietveld list <[email protected]<mailto:[email protected]>>
Subject: [EXTERNAL] Mounting Sample on High Temperature XRD Ribbon Heater





I am looking for advice on how to prepar a HTXRD sample (mounting techniques, 
stage preparation, etc...). The ribbon heater is tantalum (brand new). The 
sample contained ammonium di-hydrogen phosphate. The atmosphere is air.



I hope to reach at least 1100C, but have had the ribbon break before 750C. 
Corrosion? or can the sample lower electrical resistance?



Please, any advice.



All the best,

Blaise








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