Germanium from Transistor

So, I recently acquired an old GE germanium transistor. These aren't used all that often, due to silicon being so much more widespread, but do contain some significant amount of pure germanium.

Here's a picture of the transistor, after exposing the inner workings with a hacksaw:



It's a bit hard to make out from my blurry phone camera, but the iridescent base is a copper heatsink. In the middle there's a circle of metal that might be indium (judging from what I looked up when I researched what's inside these things), followed by the rectangular piece of what I know to be Ge, and finally another little blob of In (maybe).



This is a closeup of the square of Ge in the middle. It's maybe half a millimeter to a millimeter thick, and about 3/16" of an inch to a side. Smaller than what I expected, but workable.

So, my question to you is: How should I get the Ge out? I read that it's resistant to acids, but I'm hesitant to use HCl or H2SO4 on it until I'm really sure that it'll work.

Quote: Originally posted by j_sum1

ec1, I was thinking of doing the exact same thing. Thanks for starting this thread. Could you please repost the pix using the SM server. Tumblr is blocked on the work computer that I am using.

I started with the biggest transistor I could find in hopes of getting a sizable chunk of Ge. If this is all that's inside, I shudder to think what lengths I'd have to go to to get it out of the smaller ones, let alone the Ge diodes I brought home.

The photos are attached.

blogfast25, that was my initial plan, but I was hoping for some mechanical means. I wonder if this will also get me some indium chloride or sulfate I can work with? Presumably not much, but still.

found some similar pics on google image search. pretty interesting, thanks for giving me something to look up
lower portion of this page has some similar pics with description
http://www.radiomuseum.org/forum/history_of_telefunken_semic...
different style pic with arrows
http://ibm-1401.info/IBM083GeNPN-withComments-.jpg

An unfortunate update. While I was handling the transistor, I tried to get that wire leading off the top of the Ge plate off in a few ways. This resulted in the Ge plate shattering, leaving me to (definitely not frantically) collect the shards of Ge:



So, on a positive note, I now have a sample (tiny as it is) of pure germanium, and I learned that you can take that wire off simply by gripping it with a pair of pliers and pulling upward - it just comes off the Ge plate, not sure why.

However, this isn't a very good-looking sample of germanium. I do have a few other transistors - they're smaller, resembling 100 uF electrolytic capacitors in both size and shape, and silver in color. The part number for these is 2SA353, for which I could find no datasheet (but the Internet was very sure these were germanium transistors). Here's one below, and next to it is what's inside:



Inside appears to be a silvery metal plate, though it's hard to tell if it's Ge or some other metal - it's coated in some kind of orange plastic. Apologies for the poor picture quality...



Who could possibly be this cruel.

Well... On another positive note, I won't have to worry about sample size if I can get that plastic off, as I have a few of these smaller transistors. They're also quite easy to take apart - just saw off the top and wiggle the lead wires around a bit, and you can actually just poke them through and out of the recently sawed-off hole in the casing.

Anyone have any ideas about getting that plastic off?

Again no visible pics.
Can you dissolve the plastic in an organic solvent?

Quote: Originally posted by j_sum1

Again no visible pics. Can you dissolve the plastic in an organic solvent?

Quote: Originally posted by elementcollector1

What solvents are typically used?

Quote: Originally posted by woelen

Why destroy such beautiful germanium transistors? The amount of Ge you get out of them is minute, while the transistors have quite some value. Germanium transistors are getting rare and expensive. If you want a nice germanium sample, then buy some off eBay. It can be obtained for three or so euros per gram, often without additional cost of shipping: http://www.ebay.nl/sch/i.html?_from=R40&_trksid=m570.l13... A 1 gram sample already is MUCH more than the tiny specks you get from a germanium transistor.

Quote: Originally posted by elementcollector1

Very true, but there's something to be said for 'making' a sample instead of buying it, even if 'making' it does consist of destroying perfectly good circuitry. Gives it a bit of a backstory, so to speak. To each their own, then.

Of course, if you want to do this, then it is your good right, no offence taken

But . . . I do not consider this 'making' germanium, it is just taking the element out of its package. The package is a little bit harder to open than the package around the germanium if you buy it off eBay, but in principle the action is similar.

If you really make and isolate germanium from an OTC product, then that would be very interesting.

Quote: Originally posted by j_sum1

Ok. but other than transistors and diodes of a certain vintage, what OTC products contain germanium?

Quote: Originally posted by woelen

I do not know of any OTC product containing germanium. My remark was more in a general sense. Maybe someone knows of some germanium-containing OTC product. BTW, a vintage germanium transistor also is not an OTC product. In the city where I live I do not think you can buy them anywhere, you need specialist sellers or someone who still has some old stock somewhere. For me a germanium transistor is as (non-)OTC as a ready made sample of germanium.

I've seen germanium medicinal supplements around, do those count?
Anyway, these were free to me because they were sitting in the back of our circuits lab, gathering dust. We're allowed to take any component as long as we use it, and they have more, so it's not like I'm doing anyone else a grave inconvenience.

Upon looking at those germanium rectifiers, they are quite expensive. There'd probably be a lot of germanium inside, though, so this bears some thought.

Quote: Originally posted by XeonTheMGPony

Old battery chargers Used Germanium rectifiers. Allot more material there. http://periodictable.com/Samples/034.2/s7s.JPG They are riveted to the back of the metal frame.

I think you are getting confused with selenium rectifiers.

Quote: Originally posted by Xenoid

Quote: Originally posted by XeonTheMGPony   Old battery chargers Used Germanium rectifiers. Allot more material there. http://periodictable.com/Samples/034.2/s7s.JPG They are riveted to the back of the metal frame. I think you are getting confused with selenium rectifiers.

Quote: Originally posted by aga

The very first radio receivers were the 'Cat's Whisker' type which used a lump of germanium with a very thin wire touching it. If you could find one of those, the content of the element i struggle to spell would be much greater.

No, aga, you are also confused!

These used the natural mineral galena, lead sulphide.