🚀 go-pugleaf

In article <13404@creare.COM>, kwg@creare.COM (Kent Goeking) writes:
>
|>   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.
|>
>
	ZnO2 based varistor materials have a negative resistance
	region. 

	- Anis