i am trying for a carbon film coating from the graphite sample (Mixture) with Electron beam evaporation set up which is available. please suggest me that whether it is possible or some other technique has to be adopted
Hi Prajwal,
I did not make such deposition personally, but I can confirm that electron beam evaporation is possible from, e.g., graphite rod. It was done in my former institute. For that one can use an EFM evaporator, however keep in mind that this process requires a lot of power and can be very challenging. Sorry that I can not provide you with more details. You can find the result of such deposition in the paper: http://www.sciencedirect.com/science/article/pii/S0008622315001311 (Fig. 1 and methods).
Best regards,
Michal
Technically, it is possible, but for what? What advantages do you expect in comparison with the well-known thermal evaporation technique?
graphite evaporation temperature is about 2400 o C at 1.33 x 10- 2 mbar vapor pressure so i was not confident to do the experiment. Thermal evaporation technique c working range is low so I am going for E beam method.
Hi Prajwal,
indeed. I think the main advantage of E-beam over thermal evaporation is that you don't have too heat up graphite to such high temperatures what usually takes a lot of time. On the other hand, e-beam is surely less stable. Good luck.
Best regards,
Michal
I'm not an expert in the carbon coating, but I weekly use thermal evaporation technique for TEM grids preparation (Jeol JEE 420 evaporator). The heating time is about 10-20 sec (few times). This old (more than 50 years) technique is well-known in electron microscopy.
There are two carbon electrodes in the vacuum chamber. One is sharped to cone and the tip area has very high (white light) temperature when the currernt is going through the electrodes.
This system is cheap, robust and works well. What advantages could have a high power e-beam system?
E-beam evaporation technique is good for metal coating, because it provides very fine grain size. But what reason can be for a conventional carbon?
Oh, I see. I was not aware of such system where you pass a high current through carbon electrodes. By thermal evaporation I had in mind standard heating up of material in crucible by resistive heating above evaporation/sublimation temperature. Your system looks simple and efficient. Never heard about such dedicated for UHV systems but if it exists, could be very convenient.
This discussion stopped a year ago, nevertheless for future readers it might be useful to add that E-beam evaporation from a graphite rod is invaluable for MBE environment, see Article Electrical and Optical Properties of Carbon Doped Cubic GaN ...
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