NetNews Usenet Archive 1992 #16/NN_1992_16.iso/spool/sci/material/586

Internet Message Format | 1992-07-30 | 1.6 KB

Xref: sparky sci.materials:586 sci.electronics:13688
Path: sparky!uunet!gatech!psuvax1!hsdndev!dartvax!fluent!creare!kwg
From: [e-mail] (Kent Goeking)
Newsgroups: sci.materials,sci.electronics
Subject: Negative resistance
Message-ID: <[e-mail]>
Date: 30 Jul 92 13:15:55 GMT
Reply-To: [e-mail] (Kent Goeking)
Followup-To: sci.materials
Organization: Creare Inc., Hanover, NH
Lines: 25


   I would like to know if there are any materials that demonstrate negative
   resistance on the macroscopic scale.  I am aware of this behavior in tunnel
   diodes but I wonder if it might not occur in other structures.

   For example, it seems plausible to me that the conductivity (albeit small)
   of a dielectric material may be sensitive to the electric field in unusual
   ways.  If leakage currents are primarily carried along grain boundaries then
   perhaps if the material was piezoelectric, under a field these current paths
   might become more restricted due to increased internal stresses.  Hence the
   resistance would increase with applied field.  A plot of V vs I in this case
   would have negative slope and thus Ohms law would be rewritten V=-IR.

   Anyone know of such a material?  Is it possible to design some sort of
   composite?  Not sure what applications it would be good for but sure would
   be a unique capability.




--
^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~
Kent Goeking ([e-mail])| "We are continually faced with a series of
Creare Inc., P.O. 71         |  opportunities brilliantly disguised as
Hanover, New Hampshire 03755 |  insoluble problems"  - John W. Gardner