1 part in 10,000,000,000 (Oct, 1954)

1 part in 10,000,000,000

To make the most of their revolutionary invention, the transistor, Bell Laboratories scientists needed ultra-pure germanium.

The scientists solved their problem by devising a radically new refining process. The germanium it yields may well be the purest commercially produced material on earth.

It has only one part in ten billion of impurities harmful to transistor performance. That’s about the same as a pinch of salt in 35 freight cars of sugar.

Yet the new process, Zone Refining, is simple in principle. An ingot of germanium is drawn through a series of induction-heating coils that melt narrow zones of the substance. Since impurities are more soluble in the liquid than in the solid form of a metal, the molten zones collect impurities. They are swept along by the successive melts to the end of the ingot, which is finally cut off.

Zone Refining is also being applied to the ultra-purification of other materials useful to telephony. This single achievement of research at Bell Telephone Laboratories clears the way for many advances in America’s telephone system.


  1. Kosher Ham says: July 21, 201010:49 am

    I wonder when they first started experimenting with silicon. I can’t imagine the Santa Clara Valley known as Germanium Valley or for that matter Gallium which is used in low noise transistors and LED’s.

  2. Firebrand38 says: July 21, 201011:46 am

    Kosher Ham: I dunno, Gallium Valley rolls off the tongue when you say it out loud.

  3. Jari says: July 21, 20105:04 pm

    And before Germanium Valley there were Selenium Valley. Hmm… sounds like a scene from Edgar Rice Burroughs’s Barsoom books….

  4. Toronto says: July 21, 20106:43 pm

    I was thinking it was a sequel to “Falcon Crest” or something. “Gallium Valley – where their conduct was always semi…”

    “You mean the novice nun who’s hiding in our pool house, Sister Michelle, isn’t really a woman?” “That’s right, his name is Michael. He’s a Trans-Sister!”

  5. r peltier says: July 22, 20109:53 am

    Thanks Toronto, transmission trans-Siberian and others have taken on a whole new meaning for me.

  6. Kosher Ham says: July 22, 201010:07 am

    Next thing we will be getting into will be organic chemistry where we will be comparing Cis and Trans Isomers. The only decent Cis isomer I know of is the Cisco Kid. There are many “trans” things out there.

  7. Firebrand38 says: July 22, 201010:37 am

    Kosher Ham: As in the Ru Paul Isomer?

  8. Kosher Ham says: July 23, 201010:16 am


    Transvestite, Transsexual, and transparent. It was part of those geeky chemistry jokes we had in college.

  9. GaryM says: July 23, 201012:33 pm

    It’s interesting that they have to start with really pure germanium, to which they then have to add controlled impurities to get the appropriate semiconductor performance.

  10. Kosher Ham says: July 24, 201011:23 am

    Ditto with silicon or similar materials such as gallium or perhaps selenium. Depending what you dope it with determines whether it is P or N material. Arsenic is often used, which can lead to a wonderful acronym for a Gallium Arsenide Field Effect Transistor or GaAsFET.

  11. Arglebarglefarglegleep says: August 6, 20102:38 pm

    Now they’re doping two forms of carbon, diamond and graphine to make experimental electronics. It’ll be interesting to see which form of carbon wins out as the next step in semiconductors.

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