Quartz ampoules coated with layer of pyrolyzed carbon
As we look back at 2015, our Quartz ampules, or ampoules, are increasingly in demand; whether they are plain or carbon coated.
Why put a layer of carbon inside your ampoule? The main reason is to prevent adhesion of material to the glass. The other reason is that open-ended ampoules can be reused, instead of breaking the glass to get the product out, as in the case of crystal growth using a Bridgman furnace.
And the “traditional” method of coating an ampoule is to use an oven and bake the carbon inside said ampoule. Only problem with that method is that the set up and completion of the work takes a long time. It is also a hit and miss proposition. Then, the ampoule has to be washed and rinsed two dozen times in between etching with Acids. The etching alone takes about 7 hours. Fill and back fill with Argon and Nitrogen at varying degrees in a kiln. Because the ampoule is resting inside an oven, you have to have all sorts of valves, bubbler, hoses and fittings to take the gases to the ampoule. You have to play with the oven temperatures. And it goes on and on. After all that, because the carbon is actually baked inside the ampoule sitting in the oven, the results are not always desirable. Before you have even had time to use it, your brand new ampoule may crack during the cooling off period. Therefore, this method can turn out to be quite expensive. It will certainly put a dent in your budget if you order carbon coated ampoules by the dozen. We are not knocking the traditional method. We simply want to save you time and money.
Sandfire Scientific has developed a method of applying light, medium or heavy layers of carbon without breaking the bank. It’s almost as easy as one, two, three. 1) you take the tube. 2) you make the ampoule. 3) you apply a layer of pyrolyzed carbon inside the ampoule.
So far, our customers have asked us to manufacture and carbon coat ampoules that have a diameter of 4mm ID to 130mm ID, and lengths of up to 500mm. Would you like plugs with your order? If you do, there is a 4th step, which is to remove the layer of carbon to your specified distance in order to facilitate sealing the ampoule with a plug.
We look forward to supplying our customers’ needs in 2016 and invite you to contact us regarding your Quartz ampoule.