CuO Conduction |
Name: Glenn C.
I am a safety instructor for 45 electric co-operatives in
Minnesota. Recently I was asked by a power line worker, which is a better
conductor- Copper or Copper Oxide. While I have been cruising around the
web, I seem to find mostly that the copper oxide works best in
superconductor applications. The line workers I instruct deal in
kilovolts in various aluminum and copper wire conductors on a daily basis
as they work at an electric utility. What is a straight forward answer I
can use? Is the copper oxide better? Is that only in superconducting
applications? Is the copper oxide found in corroded (when exposed to the
weather) copper connections related? If so, then why does it act as
resistance at typical ambient temperatures?
At temperatures your workers will encounter, copper metal is a MUCH better
conductor than copper oxide. The new "high temperature" superconductors
(which actually are superconducting only at temperatures far below that of
dry ice) contain copper and oxygen, but they also must contain other
elements, such as yttrium and barium, as well. Copper oxide alone doesn't
do the trick.
Richard E. Barrans Jr., Ph.D.
PG Research Foundation, Darien, Illinois
Metal oxides are generally not very good conductors, in fact, most are
dielectrics and hence non-conductors. Some metal oxides are semi-conductors
(and also super conductors at low temperature in some cases). Certainly,
copper and aluminum are much better conductors than their corresponding
oxides at any temperature linemen will encounter.
Copper, lead, and aluminum oxides formed by corrosion are decidedly poor
conductors. I am not an electrical engineer but I know if I let the terminals
of a battery become corroded, the battery no longer delivers electricity
(i.e. the corrosion products are insulators).
Superconductivity -- the disappearance of electrical resistance -- only
operates at very low temperatures obtainable only in labs at the present
time -- although there is a lot of research seeking higher temperature
Most metals, including copper and aluminum, form thin metal oxide film
layers when exposed to air for even a brief time -- this is what makes a new
penny turn dull after a few days or weeks. These oxide layers are so thin
however that for all practical purposes they do not interfere with the
conductivity across such layers.
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Update: June 2012